U.S. patent application number 13/929452 was filed with the patent office on 2013-11-07 for base station apparatus, user equipment, and communication control method.
The applicant listed for this patent is NTT DOCOMO, INC.. Invention is credited to Hiroyuki Ishii, Anil Umesh.
Application Number | 20130294372 13/929452 |
Document ID | / |
Family ID | 49584950 |
Filed Date | 2013-11-07 |
United States Patent
Application |
20130294372 |
Kind Code |
A1 |
Ishii; Hiroyuki ; et
al. |
November 7, 2013 |
BASE STATION APPARATUS, USER EQUIPMENT, AND COMMUNICATION CONTROL
METHOD
Abstract
A base station apparatus capable of communicating with a user
equipment terminal using a downlink shared channel is disclosed.
The base station apparatus includes a radio resource allocation
unit allocating radio resource blocks to the shared channel after
allocating the radio resource blocks to at least one of a
synchronization signal, a common control channel, a broadcast
channel, a paging channel, an MBMS channel, and a random access
response channel.
Inventors: |
Ishii; Hiroyuki;
(Yokosuka-shi, Kanagawa, JP) ; Umesh; Anil;
(Yokohama-shi, Kanagawa, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
NTT DOCOMO, INC. |
Tokyo |
|
JP |
|
|
Family ID: |
49584950 |
Appl. No.: |
13/929452 |
Filed: |
June 27, 2013 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
12528817 |
Nov 9, 2009 |
8503388 |
|
|
13929452 |
|
|
|
|
Current U.S.
Class: |
370/329 |
Current CPC
Class: |
H04W 72/042 20130101;
H04W 72/0406 20130101; H04W 72/1273 20130101; H04W 72/0446
20130101 |
Class at
Publication: |
370/329 |
International
Class: |
H04W 72/04 20060101
H04W072/04 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 1, 2007 |
JP |
2007-052115 |
Jun 19, 2007 |
JP |
2007-161938 |
Dec 20, 2007 |
JP |
2007-329024 |
Claims
1.-13. (canceled)
14. A base station apparatus capable of communicating with a user
equipment terminal using a downlink shared channel, the base
station apparatus comprising: a path loss calculation unit
configured to calculate a path loss value between the user
equipment terminal and the base station apparatus; and an
allocation unit configured to, when the path loss value is greater
than a predetermined threshold value, allocate frequency resources
having higher frequencies as frequency resources for the downlink
shared channel.
15. A base station apparatus capable of communicating with a user
equipment terminal using a downlink shared channel, the base
station apparatus comprising: a path loss calculation unit
configured to calculate a path loss value between the user
equipment terminal and the base station apparatus; and an
allocation unit configured to allocate resource groups, wherein in
a case where frequency resources for the downlink shared channel
includes plural resource groups, when the path loss value is
greater than a predetermined first threshold value, the allocation
unit allocates resource groups having higher frequencies as the
frequency resources for the downlink shared channel, when the path
loss value is equal to or less than the predetermined first
threshold value and a fading frequency is greater than a
predetermined second threshold value, the allocation unit allocates
both resource groups having higher frequencies and resource groups
having lower frequencies as the frequency resources for the
downlink shared channel, and when the path loss value is equal to
or less than the predetermined first threshold value and the fading
frequency is equal to or less than the predetermined second
threshold value, the allocation unit allocates resource groups
having higher downlink radio quality information as the frequency
resources for the downlink shared channel.
16.-20. (canceled)
Description
TECHNICAL FIELD
[0001] The present invention generally relates to a mobile
communication system employing an Orthogonal Frequency Division
Multiplexing (OFDM) scheme, and more particularly to a base station
apparatus, user equipment, and a communication control method to be
used in the same system.
BACKGROUND ART
[0002] As a next-generation system of the W-CDMA (Wideband Code
Division Multiple Access) and the HSDPA (High Speed Downlink Packet
Access), an LTE system has been studied by 3GPP (3.sup.rd
Generation Partnership Project) which is a standards body of the
W-CDMA. In the LTE system as a radio access system, an OFDM
(Orthogonal Frequency Division Multiplexing) scheme and an SC-FDMA
(Single-Carrier Frequency Division Multiple Access) scheme have
been studied to be applied to the downlink communications system
and the uplink communications system, respectively (see, for
example, Non Patent Document 1).
[0003] In the OFDM scheme, a frequency band is divided into plural
sub-carriers having narrower frequency bands, and data are
transmitted on each sub sub-carrier and the sub-carriers are
closely arranged so as not to interfere with each other, so that
fast data transmission can be achieved and an efficiency use of the
frequency band can be improved.
[0004] In the SC-FDMA scheme, a frequency band is divided in a
manner so that different frequencies can be separately used among
plural terminals (user equipment terminals) and as a result,
interferences between terminals can be reduced. Further, in the
SC-FDMA scheme, a range of transmission power fluctuation can be
made smaller; therefore lower energy consumption of terminals can
be achieved and a wider coverage area can be obtained.
[0005] The LTE system is a communication system using shared
channels in both downlink and uplink. For example, in downlink, a
base station apparatus selects a mobile station (user equipment
terminal) to communicate using the shared channel with respect to
each sub-frame (each 1 ms) and transmits the shared channel to the
selected mobile station. In this case, a process of selecting the
mobile station to communicate as described above is called a
scheduling process.
[0006] Further, in the LTE system, so-called Adaptive Modulation
and Coding (AMC) is applied; therefore, transmission formats of the
shared channels may vary among different sub-frames. Herein, the
transmission format includes various information items indicating
such as allocation information of the resource blocks which are
frequency resources, modulation scheme, payload size, HARQ (Hybrid
Automatic Repeat reQuest) information such as a Redundancy version
parameter, a process number and the like, the number of streams,
and a Pre-coding vector.
[0007] In the LTE system, identification information identifying
the mobile station that communicates by using the shared channel in
the sub-frame and the transmission format of the downlink shared
channel are reported using Downlink Scheduling Information to be
mapped to a Physical Downlink Control Channel (PDCCH). The Physical
Downlink Control Channel (PDCCH) may also be called a DL L1/L2
Control Channel. [0008] Non Patent Document 1: 3GPP TR 25.814
(V7.0.0), "Physical layer Aspects for Evolved UTRA," June 2006
DISCLOSURE OF INVENTION
Problems to be Solved by the Invention
[0009] When the scheduling process or a process of determining the
transmission format is not adequately controlled, the transmission
characteristics or radio capacity of the system may be
impaired.
[0010] Further, all the user equipment terminals being connected
are treated as targets of the scheduling; therefore, effective
scheduling may not be feasible.
[0011] The present invention is made in light of the problems and
may provide a base station apparatus and a communication control
method capable of, in LTE downlink, adequately performing the
scheduling process and the determination process of the
transmission formats in the AMC (Adaptive Modulation and Coding)
scheme.
Means for Solving the Problems
[0012] According to an aspect of the present invention, there is
provided a base station apparatus capable of communicating with a
user equipment terminal using a downlink shared channel. The base
station apparatus includes
[0013] a radio resource allocation unit allocating radio resource
blocks to the shared channel after allocating the radio resource
blocks to at least one of a synchronization signal, a common
control channel, a broadcast channel, a paging channel, an MEMS
channel, and a random access response channel.
[0014] According to another aspect of the present invention, there
is provided a base station apparatus capable of communicating with
a user equipment terminal using a downlink shared channel. The base
station apparatus includes
[0015] a transmission unit, when a system bandwidth is 5 MHz,
transmitting a broadcast channel mapped to a group of sub-carriers
shifted from resource blocks to which the downlink shared channel
is mapped by 90 kHz.
[0016] According to another aspect of the present invention, there
is provided a base station apparatus capable of communicating with
a user equipment terminal using a downlink shared channel. The base
station apparatus includes
[0017] a radio resource allocation unit allocating radio resources
using a first resource allocation method for dynamically allocating
the radio resources and a second resource allocation method for
allocating the radio resources at a constant period, wherein
[0018] after the resource blocks are allocated using the second
resource allocation method, the resource blocks are allocated using
the first resource allocation method.
[0019] According to another aspect of the present invention, there
is provided a base station apparatus capable of communicating with
a user equipment terminal using a downlink shared channel. The base
station apparatus includes
[0020] a first offset unit performing an offset process with
respect to downlink radio quality information reported from the
user equipment terminal based on acknowledgement information with
respect to the downlink shared channel and downlink required
quality;
[0021] a second radio quality information offset unit performing an
offset process with respect to the downlink radio quality
information based on priority levels determined depending on data
types;
[0022] a transmission format determination unit determining a
transmission format of the downlink shared channel based on the
downlink radio quality information on which the offset process is
performed; and
[0023] a transmission unit transmitting the downlink shared channel
using the determined transmission format of the downlink shared
channel.
[0024] According to another aspect of the present invention, there
is provided a base station apparatus capable of communicating with
a user equipment terminal using a shared channel in downlink. The
base station apparatus includes
[0025] a transmission unit, when there are two or more
retransmission data, preferentially transmitting retransmission
data having the longest time period from being stored in a data
queue to a current time using the shared channel.
[0026] According to another aspect of the present invention, there
is provided a base station apparatus capable of communicating with
a user equipment terminal using a downlink shared channel. The base
station apparatus includes
[0027] a transmission unit, in a case where there are data to be
newly transmitted having a higher priority level and data to be
retransmitted having a lower priority level and when there is an
HARQ process allocatable to the data to be newly transmitted,
transmitting the data to be newly transmitted having the higher
priority level using the shared channel; and
[0028] a transmission unit, in a case where there are data to be
newly transmitted having a higher priority level and data to be
retransmitted having a lower priority level and when there is no
HARQ process allocatable to the data to be newly transmitted,
transmitting the data to be retransmitted having the lower priority
level using the shared channel.
[0029] According to another aspect of the present invention, there
is provided a base station apparatus capable of communicating with
a user equipment terminal using a downlink shared channel. The base
station apparatus includes
[0030] a transmission unit preferentially transmitting a MAC-layer
control signal using the shared channel.
[0031] According to another aspect of the present invention, there
is provided a base station apparatus capable of communicating with
user equipment terminals using downlink shared channels. The base
station apparatus includes
[0032] a selection unit selecting user equipment terminals to which
the downlink shared channels are to be transmitted; and
[0033] a resource allocation unit sequentially allocating frequency
resources with respect to the user equipment terminals to which the
downlink shared channels are to be transmitted, wherein
[0034] the resource allocation unit allocates allocatable frequency
resources so that the allocatable frequency resources can be evenly
allocated to the user equipment terminals to which no frequency
resources have been allocated from among the user equipment
terminals to which the downlink shared channels are to be
transmitted.
[0035] According to another aspect of the present invention, there
is provided a base station apparatus capable of communicating with
a user equipment terminal using a shared channel in downlink. The
base station apparatus includes
[0036] a storage unit associating and storing radio resources
usable for transmitting the shared channel and downlink radio
quality information with a transmission method to be used in the
transmission of the shared channel;
[0037] a determination unit determining the transmission method to
be used in transmission of the shared channel by referring to the
storage unit and based on downlink radio quality information
reported from the user equipment terminal and radio resources
usable for the shared channel; and
[0038] a transmission unit transmitting the shared channel using
the determined transmission method.
[0039] According to another aspect of the present invention, there
is provided a base station apparatus capable of communicating with
a user equipment terminal using a downlink shared channel. The base
station apparatus includes
[0040] a path loss calculation unit calculating a path loss value
between the user equipment terminal and the base station apparatus;
and
[0041] an allocation unit, when the path loss value is greater than
a predetermined threshold value, allocating frequency resources
having higher frequencies as frequency resources for the downlink
shared channel.
[0042] According to another aspect of the present invention, there
is provided a base station apparatus capable of communicating with
a user equipment terminal using a downlink shared channel. The base
station apparatus includes
[0043] a path loss calculation unit calculating a path loss value
between the user equipment terminal and the base station apparatus;
and
[0044] an allocation unit allocating resource groups, wherein
[0045] in a case where frequency resources for the downlink shared
channel includes plural resource groups,
[0046] when the path loss value is greater than a predetermined
first threshold value, the allocation unit allocates resource
groups having higher frequencies as the frequency resources for the
downlink shared channel,
[0047] when the path loss value is equal to or less than the
predetermined first threshold value and a fading frequency is
greater than a predetermined second threshold value, the allocation
unit allocates both resource groups having higher frequencies and
resource groups having lower frequencies as the frequency resources
for the downlink shared channel, and
[0048] when the path loss value is equal to or less than the
predetermined first threshold value and the fading frequency is
equal to or less than the predetermined second threshold value, the
allocation unit allocates resource groups having higher downlink
radio quality information as the frequency resources for the
downlink shared channel.
[0049] According to another aspect of the present invention, there
is provided a base station apparatus capable of communicating with
a user equipment terminal using a downlink shared channel. The base
station apparatus includes
[0050] a setting unit setting up an upper limit value of an amount
of frequency resources to be allocated to the downlink shared
channel, wherein
[0051] when an instruction to reduce a downlink data rate is
received from the user equipment terminal, the setting unit
decreases the upper limit value of the amount of frequency
resources.
[0052] According to another aspect of the present invention, there
is provided a base station apparatus capable of communicating with
a user equipment terminal using a downlink shared channel. The base
station apparatus including
[0053] a setting unit setting up an upper limit value of a number
of bits to be transmitted via the downlink shared channel,
wherein
[0054] when an instruction to reduce a downlink data rate is
received from the user equipment terminal, the setting unit
decreases the upper limit value of the number of bits.
[0055] According to another aspect of the present invention, there
is provided a user equipment terminal capable of communicating with
a base station apparatus using a downlink shared channel. The user
equipment terminal includes
[0056] a receiving unit, when a system bandwidth is 5 MHz,
receiving a broadcast channel mapped to a group of sub-carriers
shifted from the resource blocks to which the downlink shared
channel is mapped by 90 kHz.
[0057] According to another aspect of the present invention, there
is provided a communication control method to be used in a base
station apparatus capable of communicating with a user equipment
terminal using a downlink shared channel. The communication control
method includes
[0058] a first offset processing step of performing an offset
process with respect to downlink radio quality information based on
acknowledgement information with respect to the downlink shared
channel and downlink required quality, the downlink radio quality
information being reported from the user equipment terminal;
[0059] a second offset processing step of performing an offset
process with respect to downlink radio quality information based on
priority levels determined depending on data types;
[0060] a determination step of determining a transmission format of
the downlink shared channel based on the downlink radio quality
information on which the first or second offset process is
performed; and
[0061] a transmission step of transmitting the downlink shared
channel using the determined transmission format of the downlink
shared channel.
[0062] According to another aspect of the present invention, there
is provided a communication control method to be used in a base
station apparatus capable of communicating with a user equipment
terminal using a downlink shared channel. The communication control
method includes
[0063] a storage step of associating and storing radio resources
usable for transmitting the shared channel and downlink radio
quality information with a transmission method used in the
transmission of the shared channel;
[0064] a determination step of determining a transmission method to
be used in the transmission of the shared channel by referring the
stored data and based on downlink radio quality information
reported from the user equipment terminal and radio resources
usable for the shared channel; and
[0065] a transmission step of transmitting the shared channel using
the determined transmission method.
Advantageous Effect of the Invention
[0066] According to an embodiment of the present invention, there
may be provided a base station apparatus, user equipment, and a
communication control method capable of, in LTE downlink,
adequately performing the scheduling process and the determination
process of the transmission formats in the AMC.
BRIEF DESCRIPTION OF THE DRAWINGS
[0067] FIG. 1 is a schematic diagram showing a configuration of a
radio communication system according to an embodiment of the
present invention;
[0068] FIG. 2 is a flowchart showing a process of a DL MAC data
transmission according to an embodiment of the present
invention;
[0069] FIG. 3 is a flowchart showing process of scheduling
coefficient calculation and candidate UE selection according to an
embodiment of the present invention;
[0070] FIG. 4 is a flowchart showing a process of control for a TER
selection according to an embodiment of the present invention;
[0071] FIG. 5 is a drawing showing resource blocks allocated to a
synchronization signal and a broadcast channel;
[0072] FIG. 6 shows a DL TF Related Table;
[0073] FIG. 7 is a partial block diagram of a base station
apparatus according to an embodiment of the present invention;
[0074] FIG. 8 is a partial block diagram of a user equipment
terminal according to an embodiment of the present invention;
[0075] FIG. 9 is a flowchart showing a process of a DL MAC data
transmission according to an embodiment of the present
invention;
[0076] FIG. 10 is a flowchart showing a process of scheduling
coefficient calculation and candidate UE selection according to an
embodiment of the present invention;
[0077] FIG. 11 is a flowchart showing a process of control for a
TFR selection according to an embodiment of the present
invention;
[0078] FIG. 12 is a flowchart showing a control process of
allocating resource block groups according to an embodiment of the
present invention;
[0079] FIG. 13 is a partial block diagram of a base station
apparatus according to an embodiment of the present invention;
[0080] FIG. 14 is a drawing showing an interference in a user
equipment terminal; and
[0081] FIG. 15 is a drawing showing a method of reducing the
interference of an uplink transmission signal to a downlink
reception signal.
EXPLANATION OF REFERENCES
[0082] 100.sub.1, 100.sub.2, 100.sub.3, 100.sub.n: USER EQUIPMENT
TERMINAL(S) [0083] 104: AMPLIFIER [0084] 106:
TRANSMISSION/RECEIVING SECTION [0085] 108: BASEBAND SIGNAL
PROCESSING SECTION [0086] 110: APPLICATION SECTION [0087] 200: BASE
STATION APPARATUS [0088] 202: MBMS SUBFRAME DETECTION SECTION
[0089] 204: PCH RACH RESPONSE DETECTION SECTION [0090] 206:
SCHEDULING COEFFICIENT CALCULATION SECTION [0091] 208: MULTIPLEXED
UE NUMBER COUNTING SECTION [0092] 210: TRANSPORT FORMAT/RESOURCE
BLOCK SELECTION SECTION [0093] 252: LAYER 1 PROCESSING SECTION
[0094] 254: USER EQUIPMENT STATUS MANAGEMENT SECTION [0095] 256:
SCHEDULING COEFFICIENT CALCULATION SECTION [0096] 258: UE SELECTION
SECTION [0097] 260: MAC CONTROL SIGNAL GENERATION SECTION [0098]
262: COMMON CH/MCH RESOURCE MANAGEMENT SECTION [0099] 264:
FREQUENCY RESOURCE MANAGEMENT SECTION [0100] 266: PERSISTENT
RESOURCE MANAGEMENT SECTION [0101] 268: TFR SELECTION SECTION
[0102] 270 (270.sub.1, 270.sub.2, . . . , 270.sub.n): MARC CONTROL
SECTION [0103] 272: RLC/PDCP PROCESSING SECTION [0104]
2721.sub.n,k: RLC BUF [0105] 300: ACCESS GATEWAY APPARATUS [0106]
400: CORE NETWORK
BEST MODE FOR CARRYING OUT THE INVENTION
[0107] Next, a best mode for carrying out the present invention is
described based on the embodiments described below with reference
to the accompanying drawings.
[0108] Throughout the figures for illustrating the embodiments of
the present invention, the same reference numerals are used for the
same or equivalent elements and the repeated descriptions thereof
may be omitted.
[0109] First, a radio communication system having a base station
apparatus according to an embodiment of the present invention is
described with reference to FIG. 1.
First Embodiment
[0110] As shown in FIG. 1, the radio communication system 1000,
which may be an Evolved UTRA (Universal Terrestrial Radio Access)
and UTRAN (UTRA Network) system (a.k.a an LTE (Long Term Evolution)
system or a super 3G system), includes a base station apparatus
(eNB: eNode B) 200 and plural user equipment (UE) 100.sub.n
(100.sub.1, 100.sub.2, 100.sub.3, . . . 100.sub.n; n: an integer
greater than zero (0)) (hereinafter, the user equipment (UE) may be
referred to as a user equipment terminal(s)). The base station
apparatus 200 is connected to an upper node station such as an
access gateway apparatus 300. The access gateway apparatus 300 is
connected to a core network 400. In this case, the user equipment
(UE) terminals 100.sub.n are in communication with the base station
apparatus 200 in a cell 50 based on the Evolved UTRA and UTRAN
radio communication scheme.
[0111] Each of the user equipment terminals (100.sub.1, 100.sub.2,
100.sub.3, . . . 100.sub.n) has the same configuration, functions,
and status. Therefore, unless otherwise described, the term user
equipment (UE) 100.sub.n may be collectively used in the following
descriptions.
[0112] As the radio access scheme in the radio communication system
1000, the OFDM (Orthogonal Frequency Division Multiplexing) scheme
and the SC-FDMA (Single-Carrier Frequency Division Multiplexing
Access) scheme are used in downlink and uplink communications,
respectively. As described above, the OFDM scheme is a
multi-carrier transmission scheme in which a frequency band is
divided into plural sub-carriers having narrow frequency bands and
data are mapped on each sub-carrier to be transmitted. The SC-FDMA
scheme is a single-carrier transmission scheme in which a frequency
band is divided so that different frequencies can be used among
plural terminals and as a result, interferences between terminals
can be reduced.
[0113] Next, communication channels used in the Evolved UTRA and
UTRAN radio communication scheme are described.
[0114] In downlink communications, a Physical Downlink Shared
Channel (PDSCH) that is shared among the user equipment terminals
100.sub.n and a Physical Downlink Control Channel (PDCCH) are used.
In downlink, user information and transport format information of a
Downlink Shared Channel, the user information and the transport
information of an Uplink Shared Channel, acknowledgement
information of the Uplink Shared Channel and the like are reported
via the Physical Downlink Control Channel (PDCCH). User data are
transmitted via the Physical Downlink Shared Channel (PDSCH). The
user data are transmitted via a Downlink Shared Channel (DL-SCH) as
a transport channel.
[0115] In uplink communication, a Physical Uplink Shared Channel
(PUSCH) that is shared among user equipment terminals 100.sub.n and
an LTE control channel are used. The LTE control channel has two
types, one is to be time-domain multiplexed with the Physical
Uplink Shared Channel (PUSCH) and the other is to be
frequency-domain multiplexed with the Physical Uplink Shared
Channel (PUSCH). The control channel to be frequency-domain
multiplexed with the Physical Uplink Shared Channel (PUSCH) is
called a Physical Uplink Control Channel (PUCCH).
[0116] In uplink communication, a downlink Channel Quality
Indicator (CQI) to be used for scheduling in downlink and an
Adaptive Modulation and Coding (AMC) and acknowledgement
information of the Downlink Shared Channel (HARQ (Hybrid Automatic
Repeat reQuest) ACK information) are transmitted via the LTE
control channel. Further, the user data are transmitted via the
Physical Uplink Shared Channel (PDSCH). The user data are
transmitted via an Uplink Shared Channel (UL-SCH) as a transport
channel.
[0117] Next, a Downlink MAC (DL MAC) data transmission procedure as
a communication control method performed in a base station
apparatus according an embodiment of the present invention is
described.
[0118] In this embodiment, a logical channel corresponds to, for
example, a Radio bearer; and a Priority class corresponds to, for
example, a priority level.
[0119] Next, an allocation unit of the transmission bandwidth of
the Physical Downlink Shared Channel (PDSCH) is described. The
allocation of the Physical Downlink Shared Channel (PDSCH) is
performed with respect to each sub-frame by treating, for example,
a Resource block group (hereinafter may be referred to as RB group)
as a unit, the RB group being defined as a system parameter. Each
RB group includes plural Resource Blocks (RBs), and a corresponding
relationship between the RBs and the RB group is set as a system
parameter via an external input interface (I/F). The allocation of
the transmission bandwidth by treating the RB group as a unit is
also performed on the Physical Downlink Shared Channel (PDSCH) to
which Persistent scheduling is applied. In the following, a case is
described where the RB group is configured. However, without
configuring the RB block, the allocation of the Physical Downlink
Shared Channel (PDSCH) may be performed by treating the resource
block as a unit.
[0120] Further, in the descriptions below, a dynamic scheduling
corresponds to a first resource allocation method of dynamically
allocating radio resources. When the dynamic scheduling is applied
to the Downlink Shared Channel (DL-SCH), radio resources are
allocated to arbitrary sub-frames with respect to the user
equipment (UE). Further, in this case, various values may be set as
the values of the transmission format including the allocation
information of the resource blocks as frequency resources,
modulation scheme, payload size, HARQ information items, such as a
Redundancy version parameter, a process number and the like, and
information items of an MIMO and the like.
[0121] On the other hand, the Persistent scheduling is a scheduling
method of allocating transmission opportunities at a predetermined
cycle in accordance with a type of data or features of the
application to transmit/receive data and corresponds to a second
resource allocation method of allocating radio resources at the
predetermined cycle. Namely when the Persistent scheduling is
applied to the Downlink Shared Channel (DL-SCH), the Downlink
Shared Channel (DL-SCH) is transmitted using predetermined
sub-frames with respect to the user equipment (UE). Further, in
this case, predetermined values are set as the values of the
transmission format including the allocation information of the
resource blocks as frequency resources, modulation scheme, payload
size, HARQ information items, such as the Redundancy version
parameter, the process number and the like, and the information
items of the MIMO and the like. Namely, the shared channel (radio
resource) is allocated to the predetermined sub-frames, and the
Downlink Shared Channel (DL-SCH) is transmitted using the
predetermined transmission format. In this case, the predetermined
sub-frames may be arranged, for example, at a predetermined cycle.
Further, the predetermined transmission format is not necessarily
fixed to one type, and so, plural types of transmission formats may
be provided.
[0122] Next, a downlink MAC data transmission procedure is
described with reference to FIG. 2. FIG. 2 shows a procedure,
starting from a scheduling process performed by calculating
scheduling coefficients, to a DL TER selection process of
determining the transport format and the RB group to be
allocated.
[0123] As shown in FIG. 2, in step S202, a DL MAC maximum
multiplexing number N.sub.DLMAX is set in the base station
apparatus 200. The DL MAC maximum multiplexing number N.sub.DLMAX
is the maximum multiplexing number in one sub-frame of the Downlink
Shared Channel (DL-SCH) to which the Dynamic Scheduling is applied
and is designated via the external input interface (I/F).
[0124] Next, in step S206, the base station apparatus 200 counts a
PCH (Paging Channel) number and an RACH (Random Access Channel)
response number in the sub-frame and defines the numbers as
N.sub.PCH and N.sub.RACHres, respectively. In this case, instead of
using actual PCH number and RACH response number, the number of
Downlink Scheduling Information for the PCH and the number of
Downlink Scheduling Information for the RACH response may be
calculated as the PCH number and the RACH response number,
respectively.
[0125] Next, in step S208, calculation of scheduling coefficients
is performed in the base station apparatus 200. The user equipment
(UE) terminals in which radio resources are allocated based on the
Dynamic scheduling in the sub-frame are selected. The number of
user equipment (UE) terminals in which the radio resources are
allocated based on the Dynamic scheduling in the sub-frame is
defined as N.sub.DL-SCH.
[0126] In step S212, a Downlink Transport format and Resource
selection (DL TFR) is performed. Namely transmission formats are
determined and the radio resources area allocated with respect to
each of a Synchronization signal (also called a Synchronization
Channel (SCH)), a Broadcast Channel (BCH), a Paging Channel (PCH),
a Random Access Channel (RACH) response (RACH response, or message2
in random access procedure), the Downlink Shared Channel (DL-SCH)
to which the Persistent Scheduling is applied, and the Downlink
Shared Channel (DL-SCH) to which the Dynamic Scheduling is
applied.
[0127] Next, the Calculation for Scheduling coefficients performed
in step S208 is described with reference to FIG. 3.
[0128] FIG. 3 shows a process of selecting the user equipment (UE)
terminal(s) in which radio resources are allocated based on the
Dynamic scheduling by calculating the Scheduling coefficients. The
base station apparatus 200 performs the following processes with
respect to all the user equipment (UE) terminals in an LTE active
state including, for example, in an RRC (Radio Resource Control)
connecting state.
[0129] As shown in FIG. 3, in step S302, formulas of n=1 and
N.sub.scheduling=0 are provided; where n denotes an index of the
user equipment terminals 100.sub.n and n=1, . . . , N (N is an
integer greater than 0).
[0130] Next, in step S304, Renewal of HARQ (Hybrid Automatic Repeat
reQuest) Entity Status is performed. In this step, in the user
equipment (UE), a process receiving ACK as the acknowledgement
information with respect to the Downlink Shared Channel (DL-SCH) is
released. Further, a process in which the maximum number of
retransmissions has been reached is also released and the user data
in the process are discarded. The maximum number of retransmissions
is set with respect to each Priority class via the external input
interface (I/F). Further, it is assumed that the maximum number of
retransmissions of MAC PDU (Protocol Data Unit), with which plural
logical channels are multiplexed, complies with the maximum number
of retransmissions of a logical channel having the highest Priority
Class.
[0131] Next, in step S306, a Measurement Gap Check is performed.
More specifically, it is determined whether the sub-frame (i.e.,
the sub-frame transmitting the Downlink Shared Channel (DL-SCH)) is
included in the Measurement Gap or whether the sub-frame receiving
the acknowledgement information (ACK/NACK) with respect to the
Downlink Shared Channel (DL-SCH) is included in the Measurement
Gap. When determining that the sub-frame is included in the
Measurement Gap or that the sub-frame receiving the acknowledgement
information (ACK/NACK) is included in the Measurement Gap, an NG
(signal) is returned, otherwise, an OK (signal) is returned. The
Measurement Gap refers to a time interval when cells operating at a
different frequency are measured for a different-frequency handover
of the user equipment (UE), and during the time interval,
communications cannot be performed and therefore, the user
equipment (UE) cannot receive the Downlink Shared Channel (DL-SCH).
Further, during the time period when measuring the cells operating
at a different frequency, the user equipment (UE) cannot transmit
the acknowledgement information (ACK/NACK). As a result, the base
station apparatus 200 cannot receive the acknowledgement
information (ACK/NACK). Accordingly, when a result of the
Measurement Gap Check is NG (NG in step S306), the user equipment
(UE) terminal is excluded from a target of the scheduling
process.
[0132] In this case, the cell operating at a different frequency
may be a cell of the Evolved UTRA and UTRAN system or a cell of
another system such as, for example, GSM, WCDMA, TDD-CDMA, CDMA
2000, or WiMAX system.
[0133] Next, in step S308, a discontinuous reception (DRX) is
checked. Namely it is determined whether the user equipment (UE) is
in DRX (Discontinuous Reception) mode. When determining that the
user equipment (UE) is in DRX mode, it is further determined
whether the sub-frame is included in a DRX reception timing. When
determining that the user equipment (UE) is in DRX (Discontinuous
Reception) mode and the sub-frame is not included in the DRX
reception timing, the "NG" is returned, otherwise the "OK" is
returned. Namely when determining that the user equipment (UE) is
not in DRX mode or that the user equipment (UE) is in DRX mode and
the sub-frame is included in the DRX reception timing, the OK is
returned. Further, in a case of not being in DRX mode, a value of
flag.sub.DRX described below is set to 0 (zero); and in a case of
being in DRX mode and in DRX reception timing, the value of
flag.sub.DRX is set to 1 (one). Herein, the DRX reception timing
refers to a timing when data can be received during in DRX mode.
Further, when a state is in DRX mode and not in the DRX reception
timing, the state corresponds to a sleep mode.
[0134] When a result of the DRX check is NG (NG in step S308), the
user equipment is excluded from a target of the scheduling
process.
[0135] Next, in step S310, an Uplink Synchronization Check (UL Sync
Check) is performed. More specifically, it is determined whether
the uplink synchronization state of the user equipment (UE) is
classified as "Synchronization loss Type B". When determining that
the uplink synchronization state is Synchronization loss Type B,
the NG is returned, and when determining that the uplink
synchronization state is not Synchronization loss Type B, the OK is
returned.
[0136] When a result of the UL Sync Check is NG (NG in step S310),
the user equipment is excluded from a target of the scheduling
process. Further, when the uplink synchronization state of the user
equipment (UE) is classified as "Synchronization loss Type A", the
user equipment is not excluded from a target of the scheduling
process.
[0137] The base station apparatus (eNB) 200 performs the following
two kinds of detections (determinations) for the uplink
synchronization state with respect to all the user equipment
terminals 100.sub.n in RRC_connected state.
[0138] First, the base station apparatus (eNB) 200 performs Power
detection of a Sounding RS (Reference signal) of the user equipment
(UE) within a range of Window 1 determined by taking the cell
radius into consideration and having a similar size of a Window to
wait for a RACH preamble. Namely when a metric used in the Power
detection of the user equipment exceeds a predetermined threshold
value, it is determined as Power detection OK, otherwise, it is
determined as Power detection NG. Further, a reflection time (which
is a time period required to determine OK or NG) in this detection
is typically in a range from 200 ms to 1,000 ms in a state while
the Sounding RS is continuously received.
[0139] Second, the base station apparatus (eNB) 200 performs FFT
timing detection to detect whether a signal of the user equipment
(UE) is included within a range of Window 2 defined based on an FET
timing and a CP (Cyclic Prefix) length. Therefore, when the signal
of the user equipment (UE) is included in the Window 2, it is
determined as FFT timing detection OK, and when there is no main
path of the user equipment (UE), it is determined as FFT timing
detection NG. Further, the reflection time (which is a time period
required to determine OK or NG) in this detection is typically in a
range from 1 ms to 200 ms in a state while the Sounding RS is
continuously received.
[0140] The "Synchronization loss Type A" refers to a
Synchronization state of the user equipment (UE) in which the
result of Power detection is determined as OK and the result of FFT
timing detection is determined as NG. On the other hand, the
"Synchronization loss Type B" refers to a Synchronization state of
the user equipment (UE) in which the result of Power detection is
determined as NG and the result of FFT timing detection is
determined as NG.
[0141] Next, in step S312, a Received CQI (Channel Quality
Indicator) Check is performed. More specifically, the base station
apparatus (eNB) 200 determines whether CQI across the system
bandwidth is received from the user equipment (UE). In a case where
the CQI across the system bandwidth is received in the sub-frame or
in a sub-frame preceding the sub-frame and the CQI across the
system bandwidth is determined as OK at least one time according to
a CQI reliability determination result, the OK is returned,
otherwise, the NG is returned. The CQI reliability determination
may be performed by, for example, calculating an SIR
(Signal-interference Ratio) of the received signal of the CQI and
determining the reliability of the CQI based on the calculated SIR.
In this case, for example, when the SIR is less than a
predetermined threshold value, the reliability of the CQI is
determined as NG, and when the SIR is equal to or greater than the
predetermined threshold value, the reliability of the CQI is
determined as OK.
[0142] When a result of the Received CQI Check is NG (NG in step
S312), the user equipment is excluded from a target of the
scheduling process. Further, in a case where the result of the
Received CQI Check is NG, even when the user equipment (UE) has a
logical channel to which Persistent Scheduling is applied, the user
equipment is excluded from a target of the scheduling process.
Further, in this case, when a Persistent Resource allocated to the
user equipment (UE) is included (allocated) in the sub-frame, the
Persistent Resource is released. Herein, the Persistent Resource
refers to a Resource block reserved for the Persistent
Scheduling.
[0143] Next, in step S314, a Persistent Scheduling Check is
performed. The Persistent scheduling is a scheduling method of
allocating transmission opportunities at a predetermined cycle in
accordance with a type of data or features of the application to
transmit/receive data. Further, the type of data may include data
of Voice Over IP, Streaming data or the like. The Voice Over IP and
the Streaming data correspond to the applications.
[0144] In step S314, it is determined whether the user equipment
(UE) has a logical channel to which Persistent Scheduling is
applied. When determining that the user equipment (UE) has a
logical channel to which Persistent Scheduling is applied, the
process goes to step S330 in which a Persistent scheduled Sub-frame
Check is performed. Otherwise, the process goes to step S316 in
which a Localized/Distributed Check is performed. In localized
(transmission), it may be advantageous to allocate relatively
consecutive frequency blocks (resource blocks) based on CQI because
a fading frequency in a propagation environment between the user
equipment (UE) and the base station apparatus 200 is (relatively)
small. On the other hand, in Distributed (transmission), it may be
advantageous to allocate frequency blocks (resource blocks) which
are relatively discretely distributed (separated) from each other
regardless of the CQI values because the fading frequency in a
propagation environment between the user equipment (UE) and the
base station apparatus 200 is (relatively) large.
[0145] In step S330, it is determined in the sub-frame whether the
Persistent resource is allocated to a logical channel to which
Persistent scheduling is applied, the user equipment (UE) having
the logical channel. When determining that the Persistent resource
is allocated to the logical channel (OK in step S330), the process
goes to step S332 in which an Assign/Release Check is performed.
When determining that the Persistent resource is not allocated to
the logical channel (NG in step S330), the process goes to step
S316 in which the Localized/Distributed Check is performed.
[0146] In step S332, it is determined whether there are
transmittable data in the logical channel of the user equipment
(UE), the Persistent scheduling being applied to the logical
channel. Namely the base station apparatus 200 determines in a data
buffer whether there are transmittable data of the logical channel
to which Persistent scheduling is applied. When determining that
there are transmittable data (Assign in step S332), the process
goes to step S334 in which a Data Size Check is performed. On the
other hand, when determining that there are no transmittable data,
the process goes to step S336 in which a Persistent resource
Release process is performed.
[0147] In step S334, it is determined whether a size of the
transmittable data of the logical channel of the user equipment is
equal to or greater than a threshold value
Threshold.sub.data.sub.--.sub.size, the Persistent scheduling being
applied to the logical channel. When determining that the size of
the transmittable data is equal to or greater than the threshold
value Threshold.sub.data.sub.--.sub.size (NG in step S334), the
process goes to step S336 in which the Persistent Resource Release
process is performed. On the other hand, when determining that the
size of the transmittable data is less than the threshold value
Threshold.sub.data.sub.--.sub.size (OK in step S334), the process
goes to step S338 in which a Persistent Resource Reservation
process is performed.
[0148] In step S338, the Persistent Resource to be allocated to the
logical channel of the user equipment (UE) is reserved, the Persist
scheduling being applied to the logical channel. Further, the
calculation of the scheduling coefficients described below is also
performed with respect to the user equipment (UE) to which the
Persistent Resource is applied in the sub-frame. Further, when the
radio resources are allocated to the logical channel to which the
Dynamic Scheduling is applied in the sub-frame, the logical channel
to which the Persistent scheduling is applied and the logical
channel to which the Dynamic scheduling is applied are multiplexed
and the MAC PDU (DL-SCH) is transmitted.
[0149] In step S336, the Persistent Resource to be allocated to the
logical channel of the user equipment (UE) is released, the
Persistent scheduling being applied to the logical channel. In this
case, it is assumed that the Persistent Resource is released with
respect to the sub-frame only, and in the timing when the next
Persistent Resource is allocated, the Assign/Release Check is newly
performed.
[0150] In step S316, the downlink transmission type of the user
equipment (UE), i.e., whether Localized (transmission) type or
Distributed (transmission) type, is determined. The transmission
type may be independently controlled (managed) between Downlink
communications and Uplink communications.
[0151] For example, when the CQI across the system bandwidth of the
user equipment (UE) is equal to or greater than a threshold value
"Threshold.sub.CQI" and an Fd estimation value is equal to or less
than a threshold value "Threshold.sub.Fd,DL", the Localized
transmission is determined. Otherwise, the Distributed transmission
is determined.
[0152] As the Fd estimation value, a value reported in an RRC
message such as a Measurement report from the user equipment (UE)
or a value calculated based on a time correlation value of the
Sounding reference signal transmitted from the user equipment (UE)
terminal may alternatively be used.
[0153] Further, in the above example, the transmission type is
determined based on both CQI value across the system bandwidth and
the Fd estimation value. However, alternatively, the transmission
type may be determined based on only the CQI value across the
system bandwidth or only the Fd estimation value.
[0154] Next, in step S318, a Buffer Status Check is performed. More
specifically, with respect to the logical channel of the user
equipment (UE), it is determined whether there are transmittable
data in the sub-frame. Namely the base station apparatus 200
determines whether there are transmittable data in the data buffer
with respect to each logical channel of the user equipment (UE).
When determining that there are no transmittable data in any of the
logical channels, the NG is returned. On the other hand, when
determining that there are transmittable data in at least one
logical channel, the OK is returned. Herein, the transmittable data
includes newly transmittable data or retransmittable data. The
logical channels do not include any logical channel that the
Persistent Resource is reserved in step S338. Namely when
transmittable data is included only in the logical channel that the
Persistent Resource is reserved in step S338, the NG is returned.
When there is only control information of an MAC layer as the
transmittable data, the control information may be treated as a
logical channel belonging to the same Priority class as a Dedicated
Control Channel (DCCH) belongs. When a result of the Buffer Status
Check is NG (NG in step S318), the user equipment is excluded from
a target of the scheduling process. On the other hand, when a
result of the Buffer Status Check is OK (OK in step S318), a
logical channel having the Highest priority is selected from among
the logical channels having transmittable data based on the
following selection logics described below and the process goes to
step S320 in which a Scheduling Coefficient Calculation process is
performed. When the logical channel having the Highest priority is
selected, the logical channel in which Persistent Resource is
reserved in step S338 is also treated as a target of the
selection.
[0155] Selection logic 1: The logical channel having the highest
priority level is defined as the logical channel having the Highest
priority.
[0156] Selection logic 2: When there are plural logical channels
satisfying the Selection logic 1, the logical channel(s) having the
transmittable data is defined as the logical channel(s) having the
Highest priority.
[0157] Selection logic 3: In a case where there are plural logical
channels satisfying the Selection logic 2, when there is a
Dedicated Control Channel (DCCH), the Dedicated Control Channel
(DCCH) is defined as the logical channel having the Highest
priority; and when there is no Dedicated Control Channel (DOOM),
any of the logical channels from among the plural logical channel
is determined as the logical channel having the Highest
priority.
[0158] When those selection logics are applied, not the
retransmission data of the logical channel having a lower priority
but the new data of the logical channel having a higher priority
are more likely to be determined as the data of the logical channel
having higher priority.
[0159] The above-described process that the user equipment (UE)
terminal is excluded from a target of the scheduling process in
steps S306, S308, S310, S312, and S318 means that the Scheduling
Coefficient Calculation process described below is not to be
performed. As a result, in the sub-frame, a Downlink Shared Channel
(DSCH) is not transmitted to the user equipment (UE) terminal. In
other words, the base station apparatus 200 performs the scheduling
with respect to the user equipment (UE) terminals other than the
user equipment (UE) terminals determined to be excluded from the
targets of the scheduling in the above steps S306, S308, S310,
S312, or S318; namely the base station apparatus 200 selects user
equipment (UE) terminals to which the shared channel is to be
transmitted and transmits downlink shared channel (DL-SCH) to the
selected user equipment (UE) terminals.
[0160] In step S320, with respect to the logical channel determined
as the logical channel having the Highest priority in step S318,
the Scheduling coefficients are calculated based on an evaluation
formula described below.
[0161] Tables 1 and 2 show parameters set via the external input
interface (I/F).
TABLE-US-00001 TABLE 1 Set with respect No Parameter name to each
Remarks 1 A.sub.pc Priority This is a Priority Class Priority level
class coefficient based on Priority Class. Priority Class refers to
an index or class indicating a priority level of data defined with
respect to each logical channel. 2 B(flag.sub.HO) UE This is a HO
(HandOver) priority level coefficient given to transmit remaining
data of UE performing Inter-eNB HO. In the sub-frame, this value is
set based on a value of flag "flag.sub.HO" related to the UE. When
flag.sub.HO = 0, B(0) is set to a fixed value 1.0 (B(0) = 1.0), and
only when flag.sub.HO = 1, this value is set via external input
interface (I/F). For example, when flag.sub.HO = 1, by setting
B(flag.sub.HO) to 2.0 (B(flag.sub.HO) = 2.0), it becomes possible
to preferentially transmit remaining data of UE performing
Inter-eNB HO. For example, when communicating between the UE and
base station apparatus 200 about the control for the Inter eNB
HO(HandOver), flag.sub.HO may be set to 1(flag.sub.HO = 1),
otherwise, flag.sub.HO may be set to 0 (flag.sub.HO = 0). 3
D(flag.sub.DRX) UE This is a DRX priority level coefficient given
to preferentially transmit data of UE in DRX mode and DRX reception
timing. In the sub-frame, this value is set based on a value of
flag "flag.sub.DRX" related to the UE. When flag.sub.DRX = 0, D(0)
is set to a fixed value 1.0 (D(0) = 1.0), and only when
flag.sub.DRX = 1, this value is set via external input interface
(I/F). For example, when flag.sub.DRX = 1, by setting
D(flag.sub.DRX) to 2.0 (D(flag.sub.DRX) = 2.0), it becomes possible
to preferentially transmit data of UE in DRX mode and DRX reception
timing.. It is assumed that in DRX mode and DRX reception timing,
flag.sub.DRX is set to 1(flag.sub.DRX = 1), otherwise, flag.sub.DRX
is set to 0 (flag.sub.DRX = 0). 4 E.sub.PC(Num.sub.retex) Priority
This is a retransmission priority coefficient class used to
preferentially transmit data to UE having a large number of
retransmission of HARQ. When there are plurality of Processes
having retransmission data, a value of the largest number of the
retransmission is defined as Num.sub.retx. Depending on the value
of the number of retransmission times, the setting value of
E.sub.PC(Num.sub.retex) is set as described above via the external
input interface (I/F). For example, as shown in the table below By
increasing the value of E.sub.PC(Num.sub.retex) as the value of
Num.sub.retx. increases, it becomes possible to preferentially
transmit data to UE having a large number of retransmission of
HARQ. Numretx setting value of EPC(Numretex) 0 1.0 1 1.2 2, 3 1.8
4-16 2.5 5 H(flag.sub.gap.sub.--.sub.control) UE This is a gap
control priority level coefficient used to preferentially transmit
data to UE in which a Measurement gap control mode is ON to measure
cells operating at a different frequency. In the sub-frame, this
value is set based on a value of flag.sub.gap.sub.--.sub.control of
UE. When flag.sub.gap.sub.--.sub.control = 0, H(0) is set to a
fixed value 1.0 (H(0) = 1.0), and only when flag.sub.DRX = 1, this
value is set via external input interface (I/F). When UE is in
Measurement gap control mode (i., e., when Measurement gap control
mode is ON), flag.sub.DRX is defined as 1 (flag.sub.DRX = 1),
otherwise flag.sub.DRX is defined as 0 (flag.sub.DRX = 0). For
example, to increase the priority level of UE where Measurement gap
control mode is ON, H(1) may be set 10 (H(1) = 10).
TABLE-US-00002 TABLE 2 Set with respect No Parameter name to each
Remarks 6 F.sub.PC(t.sub.RLC.sub.--.sub.buffered) Priority This is
a residence time priority level class coefficient used to
preferentially transmit data to UE in which buffer residence time
of RLC is long. The buffer residence time of RLC SDU related to a
logical channel having the Highest priority is used as an argument.
The definition of buffer residence time of RLC SDU is defined as an
elapsed time (unit: ms) from when "RLC SDU" is stored in Queue
buffer provided with respect to each logical channel. Herein the
timing of "when RLC SDU is stored in Queue buffer" is the same
between for the retransmission and for the initial transmission. If
there are RLC SDU having different Buffer residence time, the RLC
SDU having the longest Buffer residence time is defined as
flag.sub.DRX. This value is set based on the the buffer residence
time "t.sub.RLC.sub.--.sub.buffered" of RLC SDU as follows:
F.sub.PC(t.sub.RLC.sub.--.sub.buffered <
Th.sub.PC.sup.(RLC.sup.--.sup.buffered)) = 0.0
F.sub.PC(t.sub.RLC.sub.--.sub.buffered .gtoreq.
Th.sub.PC.sup.(RLC.sup.--.sup.buffered)) = 1.0 As described above,
by increasing the value F.sub.PC(t.sub.RLC.sub.--.sub.buffered)
when the buffer residence time "t.sub.RLC.sub.--.sub.buffered" of
RLC SDU exceeds a predetermined value
Th.sub.PC.sup.(RLC.sup.--.sup.buffered), it becomes possible to
preferentially transfer data to UE having longer Buffer residence
time of RLC. 7 Th.sub.pc.sup.(RLC.sup.--.sup.buffered) Priority
This is a threshold value related to the Buffer class residence
time of the RLC SDU. 8 G(flag.sub.control) UE This is a MAC control
block priority level coefficient used to preferentially transfer
data to UE having MAC control block to be transmitted. In the
sub-frame, this value is set based on a value of flag.sub.control
of UE. When flag.sub.control = 0, G(0) is set to a fixed value 1.0
(G(0) = 1.0), and only when flag.sub.control = 1, this value is set
via external input interface (I/F). For example, when
flag.sub.control = 1, by setting G(flag.sub.control) to 2.0
(G(flag.sub.control) = 2.0), it becomes possible to preferentially
transmit remaining data of UE having the MAC control block to be
transmitted. It is assumed that when there is MAC control block to
be transmitted, flag.sub.control is set to 1(flag.sub.oontrol = 1),
otherwise, flag.sub.control is set to 0 (flag.sub.control = 0).. 9
R.sub.pc.sup.(target) Priority This is a target data rate
(bits/sub-frame) class 10 .alpha..sup.(CQI) UE This is a weighting
coefficient with respect to priority level based on CQI. By using
this parameter, it becomes possible to put weighting on priority
levels based on CQI. 11 .alpha..sub.pc.sup.(retx) Priority This is
a weighting coefficient with respect to class priority level based
on the number of HARQ retransmissions. By using this parameter, it
becomes possible to put weighting on priority levels based on the
number of HARQ retransmissions. 12
.alpha..sub.pc.sup.(RLC.sup.--.sup.bufferred) Priority This is a
weighting coefficient with respect to class priority levels based
on Buffer residence amount of RLC. By using this parameter, it
becomes possible to put weighting on priority levels based on the
Buffer residence amount of RLC. 13 .alpha..sub.pc.sup.(freq)
Priority This is a weighting coefficient with respect to class
priority levels based on frequency of allocations.. By using this
parameter, it becomes possible to put weighting on priority levels
based on the frequency of allocations. 14 .alpha..sub.pc.sup.(rate)
Priority This is a weighting coefficient with respect to class
priority levels based on Average Data Rate.. By using this
parameter, it becomes possible to put weighting on priority levels
based on the Average Data Rate. 15 .delta.'.sub.pc Priority A
convergence value of user data speed class averaging forgetting
coefficient for R.sub.n, k 16 .tau.'.sub.pc Priority A convergence
value of allocation frequency class averaged forgetting coefficient
used in calculating freq.sub.n, k. 17 Scheduling Priority An index
of Scheduling priority group set with priority group class respect
to each Priority class. Prioritization index of each UE is
performed in the order of "Scheduling priority group: High .fwdarw.
Middle .fwdarw. Low". Further, in each of the Scheduling priority
groups, prioritization is performed based on scheduling
coefficients. The priority order of the scheduling priority group
is defined as follows: High > Middle > Low.
[0162] Tables 3 and 4 show input parameters given to each logical
channel of each user equipment (UE) with respect to each Sub-frame
as a unit.
TABLE-US-00003 TABLE 3 No. Parameter name Remarks 1 PC.sub.n, k
This parameter indicates Priority Class of the logical Channel #k
of UE#n. Priority class refers to an index or class indicating a
priority level of data defined with respect to each logical
channel. 2 R.sub.n This parameter indicates Instantaneous
transmittable Data Rate (bits/sub-frame) of UE#n calculated based
on the following formula: Rn = DL_Table_TF_SIZE(RB_all, L
CQIreceived .right brkt-bot.) Where RB_all: the number of RBs
across the system bandwidth Further, "CQIreceived" is calculated as
follows: (when DL transmission type = Distributed) CQIreceived =
CQI related to across the system bandwidth (when DL transmission
type = Localized) CQIreceived = CQI of RBgroup having the highest
quality The definition of the RBgroup corresponds to the definition
of the RB groups of CQI reported from UE. 3 R.sub.n, k This
parameter indicates the Average Data Rate (bits/sub-frame) of
logical channel #k of UE#n. R.sub.n, k(TTI) = .delta..sub.n, k
R.sub.n, k (TTI - 1) + (1 - .delta..sub.n, k)*r.sub.n, k r.sub.n,
k: instantaneous data rate As the initial value of R.sub.n, k,
R.sub.n, k calculated in the sub-frame is used. .delta..sub.n, k:
forgetting coefficient which is a variable changing with respect to
each calculation period. Calculation of R.sub.n, k is performed at
every sub- frame based on update timing with respect to not only a
logical channel having the Highest Priority but also any other
logical channels.
TABLE-US-00004 TABLE 4 4 freq.sub.n,k This parameter indicates a
time-average value of allocation frequency of logical channel #k of
UE #n. An averaging section (time) is designated by T.sub.t. Namely
Freq.sub.n,k(TTI) = T.sub.n,k * freq.sub.n,k (TTI-1) +
(1-T.sub.n,k)* Allocated.sub.n,k Where, Allocated.sub.n,k is set to
1 when DL-SCH is allocated to the data of logical channel #k of UE
#n in the sub-frame where there are data to be transmitted of
logical channel #k of UE #n in data buffer; otherwise,
Allocated.sub.n,k is set to 0. Further, the update is to be
performed with respect to each sub-frame when there are data to be
transmitted of logical channel #k of UE #n in the data buffer.
Calculation of "freq.sub.n,k" is performed at every sub- frame
based on update cycle with respect to not only a logical channel
having the Highest Priority but also any other logical channels. 5
Freq.sub.PC This parameter indicates a value by averaging
"freq.sub.n,k" using UE# and logical channel # of the Priority
class. Averaging is performed with respect to only UE# and logical
channel # having data to be transmitted in the data buffer at the
sub-frame. Namely calculated as follows: Freq PC = ( n , k
.di-elect cons. PC ) Scheduling frrq n , k ( n , k .di-elect cons.
PC ) Scheduling 1 ##EQU00001## Where ( n , k .di-elect cons. PC )
Scheduling denotes the sum ( .SIGMA. ) of " UE # n and ##EQU00002##
logical channels #k having Priority Class and there is data to be
transmitted in the Buffer queue at the previous sub-frame"
[0163] Based on the input parameters in Tables 1 and 2, the
Scheduling coefficient C.sub.n of the logical channel #h having the
Highest priority of the user equipment (UE) terminal #n is
calculated based on formula (1) below.
C.sub.n=A.sub.PC.sub.h.times.B(flag.sub.HO).times.D(flag.sub.DRX).times.-
.alpha..sup.(CQI)R.sub.n.times.(1+.alpha..sub.PC.sub.h.sup.(retx)E.sub.PC.-
sub.h(retx)+.alpha..sub.PC.sub.h.sup.(RLC.sup.--.sup.buffered)F.sub.PC.sub-
.h(t.sub.RLC.sub.--.sub.buffered)).times.G(flag.sub.control).times.exp(.al-
pha..sub.PC.sub.h.sup.(freq)(Freq.sub.PC-freq.sub.n,h)+.alpha..sub.PC.sub.-
h.sup.(rate)(R.sub.n,h.sup.(target)- R.sub.n,h)) (1)
[0164] Alternatively, the Scheduling coefficient C.sub.n of the
logical channel #h having the Highest priority of the user
equipment (UE) terminal #n may be calculated based on formula (1')
below.
C.sub.n=A.sub.PC.sub.h.times.B(flag.sub.HO).times.D(flag.sub.DRX).times.-
H(flag.sub.gap.sub.--.sub.control).times..alpha..sup.(CQI)R.sub.n.times.(1-
+.alpha..sub.PC.sub.h.sup.(retx)E.sub.PC.sub.h(retx)+.alpha..sub.PC.sub.h.-
sup.(RLC.sup.--.sup.buffered)F.sub.PC.sub.h(t.sub.RLC.sub.--.sub.buffered)-
).times.G(flag.sub.control).times.exp(.alpha..sub.PC.sub.h.sup.(freq)(Freq-
.sub.PC-freq.sub.n,h)+.alpha..sub.PC.sub.h.sup.(rate)(R.sub.n,h.sup.(targe-
t)- R.sub.n,h)) (1')
[0165] In formula (1'), a term of
"H(flag.sub.gap.sub.--.sub.control)" is added to the formula (1).
The "flag.sub.gap.sub.--.sub.control" is a flag indicating whether
the user equipment (UE) is in a Measurement gap control mode.
Herein, the Measurement gap control mode indicates whether a
Measurement gap for measuring cells operating at a different
frequency is being applied. When the Measurement gap control mode
is ON, the Measurement gap is set at a predetermined timing. The
Measurement gap is set from the base station apparatus.
[0166] Generally, in the sub-frame where the Measurement gap is
applied, data cannot be transmitted and received. Therefore, it is
necessary to allocate the radio resources to the user equipment #n
to preferentially transmit and receive data in the sub-frame to
which the Measurement gap is not applied. For example, by setting
H(flag.sub.gap.sub.--.sub.control) to 10
(H(flag.sub.gap.sub.--.sub.control)=10) in a case of
flag.sub.gap.sub.--.sub.control (i.e., Measurement gap control
mode:ON) and H(flag.sub.gap.sub.--.sub.control) is set to 1
(H(flag.sub.gap.sub.--.sub.control)=1) in a case of
flag.sub.gap.sub.--.sub.control=0 (i.e., Measurement gap control
mode:OFF), it may become possible to perform the operation that
"transmission and reception of data are preferentially performed
with respect to the sub-frames to which the Measurement gap is not
applied".
[0167] By the Measurement Gap Check in step S306, when the
Measurement gap control mode is ON and when the sub-frame is
included in the Measurement gap or the sub-frame where the
acknowledgement information (ACK/NACK) is to be received is
included in the Measurement gap, this process in step S320 is not
performed. In other words, when the Measurement gap control mode is
ON and when this process in step S320 is to be performed, the
sub-frame is at a timing when signals in the same (original)
frequency are transmitted and received in a mode when cells
operating at a different frequency are being measured. Namely due
to the term "H(flag.sub.gap.sub.--.sub.control)" it may become
possible to preferentially allocate the shared channel to the
mobile station (user equipment (UE) terminal) transmitting and
receiving the same (original) frequency in a mode when cells
operating at a different frequency are being measured.
[0168] In a case of Intra-eNB Hand Over (Intra-eNB HO), it is
assumed that the measurement value and calculation value used for
the scheduling are also used in a Target eNB (eNB of Handover
destination).
[0169] In step S320, an Average Data Rate is measured. The Average
Data Rate is calculated using formula (2).
R.sub.n,k=R.sub.n,k(N.sub.n,k=1)
R.sub.n,k(TTI)=.delta..sub.n,k
R.sub.n,k(TTI-1)+(1-.delta..sub.n,k)r.sub.n,k(N.sub.n,k>1)
(2)
[0170] Where, N.sub.n,k(1, 2, . . . ) denotes the number of
updating the Average Data Rate. However, in the sub-frame where
N.sub.n,k=0, the following formula (3) is applied.
R.sub.n,k=R.sub.n,k (3)
[0171] Further, a forgetting coefficient .delta..sub.n,k is
calculated as follows.
.delta..sub.n,k=min(1-1/N.sub.n,k,.delta..sub.PCn,k)
[0172] An updating timing of the Average Data Rate is based on
"every sub-frame where there are data to be transmitted in the data
buffer of the base station apparatus 200". Further, r.sub.n,k is
calculated as "a size of transmitted MAC SDU". Namely the
calculation of the Average Data Rate is performed based on any of
the following operations in the sub-frame when the Average Data
Rate is to be updated.
[0173] 1. For a user equipment (UE) terminal that transmits data,
the Average Data Rate is calculated assuming "r.sub.n,k=size of
transmitted MAC SDU".
[0174] 2. For a user equipment (UE) terminal that has not
transmitted data, the Average Data Rate is calculated assuming
"r.sub.n,k=0".
[0175] In this case, the Average Data Rate is calculated when the
result of the Received CQI check is OK and conditions of updating
the Average Data Rate is matched. Namely the calculation is started
after the CQI is received at least once.
[0176] Next, in step S322, N.sub.Scheduling indicating the number
of user equipment (UE) terminals that calculate the Scheduling
coefficient is increased by 1 (one). In step S324, a value of "n"
indicating the index of the user equipment (UE) terminal is
increased by 1 (one).
[0177] Next, in step S326, it is determined whether the value of
"n" is equal to or less than N. When determining that the value of
"n" is equal to or less than N (YES in step S326), the process goes
back to step S304.
[0178] On the other hand, when determining that the value of "n" is
greater than N(NO in step S326), the process goes to step S328 in
which a UE Selection process is performed. More specifically, in
step S328, the user equipment (UE) terminal is selected in which
the allocation of the radio resources is performed based on the
Dynamic scheduling with respect to the sub-frame.
[0179] First, by the following formula, the number of user
equipment (UE) terminals in which the radio resources are allocated
based on the Dynamic scheduling (i.e., the number of user equipment
(UE) terminals that transmit the Downlink Shared Channel (DL-SCH))
N.sub.DL-SCH is calculated. Herein, a symbol N.sub.Scheduling
denotes the number of user equipment (UE) terminals in which the
Scheduling Coefficient Calculation process has been performed (see
FIG. 3).
N.sub.DL-SCH=min(N.sub.Scheduling,N.sub.DLMAX-N.sub.PCH-N.sub.RACHres)
(4)
[0180] Next, top N.sub.DL-SCH user equipment (UE) terminals in
which the resource blocks are to be allocated based on the Dynamic
scheduling are selected in the descending order of the Scheduling
coefficients calculated in step S320 with respect to each
Scheduling priority group of the logical channel having the Highest
priority. Namely user equipment (UE) terminals that become the
transmission destinations of the downlink Shared Channel (DL-SCH)
are selected. Herein, the Scheduling priority group refers to a
group prioritized in the Scheduling process and a Scheduling
priority group to which the logical channel is to belong is defined
with respect to each logical channel.
[0181] The above "user equipment (UE) terminals" are selected in
accordance with the order described below.
[0182] When the user equipment (UE) terminal has control
information of the MAC layer to be transmitted in the sub-frame,
the Scheduling priority group is set to "High" regardless of the
Scheduling priority group of the logical channel having the Highest
priority. [0183] High(1.sup.st).fwdarw.High(2.sup.nd).fwdarw. . . .
.fwdarw.Middle(1.sup.st).fwdarw.Middle(2.sup.nd).fwdarw. . . .
.fwdarw.Low(1.sup.st).fwdarw.Low(2.sup.nd).fwdarw. . . . .
[0184] As described above, it may become possible to calculate the
Scheduling coefficients with respect to each user equipment (UE)
terminal that is determined to be able to transmit the downlink
shared channel (DL-SCH) by performing a loop process with respect
to "n" which is an index of the user equipment (UE index). Further,
the radio resources are allocated to the user equipment (UE)
terminals having a greater calculated Scheduling coefficient value.
Namely, by controlling the transmission of the downlink shared
channel (DL-SCH), in which DL-SCH is transmitted to the user
equipment (UE) terminals having larger scheduling coefficients, it
may become possible to determine the user equipment (UE) terminals
to which the radio resources (downlink shared channel (DL-SCH)) are
allocated and transmit the downlink shared channel (DL-SCH) to the
user equipment (UE) terminals based on a priority level of data,
radio quality information reported from the user equipment (UE)
terminals, the number of retransmission, whether there is control
information of the MAC layer, frequency of allocation, an average
data rate, and a target data rate, whether the handover process is
being performed, whether it is in a reception timing of an
intermittent reception process, whether it is in a residence time
of data in an RLC (Radio Link Control) layer, and whether it is in
a reception timing in a mode of measuring cells operated at a
different frequency.
[0185] In the above example, the Scheduling priority group has
three types, High, Middle, and Low. However, four or more types of
the Scheduling priority group may be provided, or two or less types
of the Scheduling priority group may be provided.
[0186] For example, five types, i.e., High.sub.MAC, High.sub.DRX,
High, Middle, and Low, of the Scheduling priority group may be
provided assuming that the priority level decreases in the order of
High.sub.MAC, High.sub.DRX, High, Middle, and Low. Further, in this
case, with respect to the user equipment (UE) terminals having an
MAC control block to be transmitted, the Scheduling priority may be
set to "High.sub.MAC" regardless of the Scheduling priority group
of the logical channel having the Highest priority. Further, with
respect to the user equipment (UE) terminal in a DRX reception
timing in DRX mode, the Scheduling priority group may be set
"High.sub.DRX" regardless of the Scheduling priority group of the
logical channel having the Highest priority. By doing this, it may
become possible to preferentially allocate the shared channel with
respect to the user equipment (UE) terminal having the MAC control
block to be transmitted and the user equipment (UE) terminal in the
DRX reception timing in DRX mode. For example, when there are user
equipment (UE) terminal(s) having the MAC control block and user
equipment (UE) terminal(s) without the MAC control block, it may
become possible to preferentially allocate the shared channel to
the user equipment (UE) terminal(s) having the MAC control block
regardless of the value of C.sub.n in formula (1).
[0187] In the above example, the priority level is set so that the
priority level decreases in the order of High.sub.MAC,
High.sub.DRX. High, Middle, and Low. However, this is just an
example only, and, for example, the priority level may be set so
that the priority level decreases in the order of High,
High.sub.MAC, High.sub.DRX, Middle, and Low.
[0188] Next, the downlink TFR Selection (DL TFR Selection) process
performed in step S212 is described with reference to FIG. 4.
[0189] FIG. 4 shows a procedure of the DL TFR selection process. By
performing this procedure, it may become possible to determine the
transmission formats of and allocate the radio resources to common
channels such as the Synchronization Signal (also called a
Synchronization channel (SCH)), the Broadcast Channel (BCH), the
Paging Channel (PCH), and the Random Access Channel (RACH) response
(RACH response, or message2 in random access procedure), the
Downlink Shared Channel (DL-SCH) to which the Persistent Scheduling
is applied, and the Downlink Shared Channel (DL-SCH) to which the
Dynamic Scheduling is applied.
[0190] First, in step S402, Resource blocks are allocated to the
Common Channels.
[0191] When the Synchronization signal is transmitted using the
sub-frame, the resource blocks shown in Table 5 are allocated to
the Synchronization signal. When the system bandwidth is 5 MHz, 10
MHz, and 20 MHz, 25, 50, and 100 resource blocks are provided in
the system bandwidth, respectively. The resource blocks have the
corresponding identification numbers starting from #0 for the
resource block at one end. The RB group including the RB allocated
to the Synchronization signal is not allocated to the downlink
shared channel (DL-SCH) to which the Dynamic Scheduling is applied.
When the system bandwidth is 10 MHz or 20 MHz, six (6) resource
blocks provided in the center portion of the system bandwidth are
allocated to the Synchronization signal. More specifically, when
the system bandwidth is 10 MHz, the resource blocks #22 through #27
are allocated to the Synchronization signal, and when system
bandwidth is 20 MHz, the resource blocks #47 through #52 are
allocated to the Synchronization signal. On the other hand, when
the system bandwidth is 5 MHz, seven (7) resource blocks in the
center portion of the system bandwidth are allocated to the
Synchronization signal. More specifically, when the system
bandwidth is 5 MHz, the resource blocks #9 through #15 are
allocated to the Synchronization signal.
[0192] The above-mentioned resource blocks allocated to the
Synchronization signal are treated as the resource blocks reserved
for the Synchronization signal to prevent the resource blocks from
being allocated to any other channel. However, not all the resource
blocks having been reserved for the Synchronization signal are
practically allocated to the Synchronization signal. Namely the
Synchronization signal is allocated to only predetermined
sub-carriers among all the resource blocks having been allocated
for the Synchronization signal. For example, the Synchronization
signal is mapped to 72 sub-carriers in the center portion of the
system bandwidth and transmitted. In this case, when the number of
the sub-carrier to which the Synchronization signal is mapped is
defined as k, the "k" may be given as follows.
k = n - 36 + N BL DL 2 , n = 0 , , 71 ( 5 ) ##EQU00003##
[0193] Where, a symbol "N.sub.BW.sup.DL" denotes the number of
sub-carriers of the entire system bandwidth. In this case, when the
system bandwidth is 5 MHz, a group of sub-carriers to which the
Synchronization signal is mapped does not correspond to the
resource blocks to which the downlink shared channel (DL-SCH) is
mapped (see FIG. 5). Namely the Synchronization signal is
transmitted as a group of sub-carriers which is shifted with
respect to the resource blocks to which the downlink shared channel
(DL-SCH) is mapped by 90 kHz (6 sub-carriers).
[0194] The transmission power of the Synchronization signal (total
of transmission power of all the resource elements (sub-carriers);
absolute value; unit is W) is defined as P.sub.SCH.
TABLE-US-00005 TABLE A RB allocated to SCH RB Nos of RB to System
bandwidth be allocated 5 MHz #9~#15 10 MHz #22~#27 20 MHz
#47~#52
[0195] When the Broadcast Channel (BCH) is transmitted via the
sub-frame, the resource blocks shown in Table B are allocated to
the Broadcast Channel (BCH). When the system bandwidth is 10 MHz or
20 MHz, six (6) resource blocks in the center portion of the system
bandwidth are allocated to the Broadcast Channel (BCH). More
specifically, when the system bandwidth is 10 MHz, the resource
blocks #22 through #27 are allocated to the Broadcast Channel
(BCH), and when system bandwidth is 20 MHz, the resource blocks #47
through #52 are allocated to the Broadcast Channel (BCH). On the
other hand, when the system bandwidth is 5 MHz, seven (7) resource
blocks in the center portion of the system bandwidth are allocated
to the Broadcast Channel (BCH). More specifically, when the system
bandwidth is 5 MHz, the resource blocks #9 through #15 are
allocated to the Broadcast Channel (BCH).
[0196] The above-mentioned resource blocks allocated to the
Broadcast Channel (BCH) are treated as the resource blocks reserved
for the Broadcast Channel (BCH) to prevent the resource blocks from
being allocated to any other channel. However, not all the resource
blocks having been reserved for the Broadcast Channel (BCH) are
practically allocated to the Broadcast Channel (BCH). Namely, the
Broadcast Channel (BCH) is allocated to only predetermined
sub-carriers among all the resource blocks having been allocated
for the Broadcast Channel (BCH). For example, the Broadcast Channel
(BCH) may be mapped to the sub-carriers having the same sub-carrier
numbers as the Synchronization signal is mapped. In this case, when
the system bandwidth is 5 MHz, a group of sub-carriers to which the
Broadcast Channel (BCH) is mapped does not correspond to the
resource blocks to which the downlink shared channel (DL-SCH) is
mapped. Namely the Broadcast Channel (BCH) is transmitted as a
group of sub-carriers which is shifted with respect to the resource
blocks to which the downlink shared channel (DL-SCH) is mapped by
90 kHz (6 sub-carriers).
[0197] Namely when the system bandwidth is 5 MHz, as shown in FIG.
5, the base station apparatus 200 transmits the Broadcast Channel
(BCH) via a group of sub-carriers shifted with respect to the
resource blocks to which the downlink shared channel (DL-SCH) is
mapped by 90 kHz (6 sub-carriers).
[0198] Further, when the system bandwidth is 5 MHz, the user
equipment (UE) terminals 100n receive the Broadcast Channel (BCH)
via a group of sub-carriers shifted with respect to the resource
blocks to which the downlink shared channel (DL-SCH) is mapped by
90 kHz (6 sub-carriers).
[0199] The transmission power of the Broadcast Channel (BCH) (total
of transmission power of all the resource elements (sub-carriers);
absolute value; unit is W) is defined as P.sub.BCH.
[0200] The Broadcast Channel (BCH) is a name as the Transport
Channel and is called a Common Control Physical Channel (CCPCH) as
a physical channel.
TABLE-US-00006 TABLE B RB allocated to BCH RB Nos of RB to System
bandwidth be allocated 5 MHz #9~#15 10 MHz #22~#27 20 MHz
#47~#52
[0201] When the Paging Channel (PCH) is to be transmitted via the
sub-frame, an RB group set via the external input interface (I/F)
is allocated to the Paging Channel (PCH). Further, a TRF selection
process may be performed in accordance with the data size of the
Paging Channel (PCH) or the number of the user equipment (UE)
terminals to transmit the Paging Channel (PCH).
[0202] When a Random Access Channel response (RACH response) or
Message2 in random access procedure is transmitted via the
sub-frame, the number "Num.sub.RB,RACHres" of resource blocks to be
allocated to the RACH response is determined based on a CQI value
"CQI.sub.RACHres(i)" used for the TRF selection process of the RACH
response and the size "Size.sub.RACHres" of the RACH response.
[0203] The size "Size.sub.RACHres" of the RACH response is
determined in accordance with the number of user equipment (UE)
terminals multiplexed on the RACH response and the transmission
purpose of the RACH.
[0204] The CQI value "CQI.sub.RACHres(i)" is set via the external
input interface (I/F) with respect to each piece of quality
information of the RACH preamble. The symbol "i" is an index of the
quality information and a value indicating the lowest quality among
the values of quality information of the user equipment (UE)
multiplexed in the RACH response (i.e., the smallest index value)
is set.
Num.sub.RB,RACHres=DL_Table_TF_RB(Size.sub.RACHres,CQI.sub.RACHres(i))
(i=0,1,2,3)
[0205] Further, until the number of the resource blocks allocated
to the RACH response exceeds Num.sub.RB,RACHres the RB groups are
sequentially allocated to the RACH response in the ascending order
of the RACH group number.
[0206] Next, in step S404, RB allocation for Persistent Scheduling
is performed. Namely the Persistent Resource reserved in step S338
is allocated to the user equipment (UE) terminals having downlink
shared channel (DL-SCH) to which the Persistent scheduling is
applied in the sub-frame. In this case, the resource blocks to be
allocated to the downlink shared channel (DL-SCH) to which the
Persistent scheduling is applied are allocated by treating the RB
group as a unit. The transmission power of the downlink shared
channel (DL-SCH) to which the Persistent scheduling is applied
(total of transmission power of all the resource elements
(sub-carriers); absolute value; unit is W) is defined as
P.sub.persist. Herein, when there are two or more user equipment
(UE) terminals having the downlink shared channel (DL-SCH) to which
the Persistent scheduling is applied, P.sub.persist represents the
total amount of the transmission power of the downlink shared
channel (DL-SCH) of all the user equipment (UE) terminals, the
Persistent scheduling being applied to the downlink shared channel
(DL-SCH).
[0207] Next, in step S406, a Calculation for Number of RBs for
PDSCH (i.e., a calculation of the number of the resource blocks of
the Physical Downlink Shared Channel (PDSCH)) is performed. More
specifically, the number of the resource blocks
"N.sub.dynamic.sup.(RB)" that can be allocated to the Physical
Downlink Shared Channel (PDSCH) using the following formula (6)
based on the maximum transmission power of the base station
apparatus 200 (hereinafter referred to as "P.sub.max": unit:W),
transmission power of Synchronization signal "P.sub.SCH",
transmission power of Broadcast Channel (BCH) "P.sub.BCH",
transmission power of Paging Channel (PCH)"P.sub.PCH", transmission
power of Random Access Channel (RACH) response "P.sub.RACHres",
transmission power of downlink shared channel (DL-SCH) to which
Persistent scheduling is applied "P.sub.persist" and transmission
power per one resource block of downlink shared channel (DL-SCH) to
which Dynamic scheduling is applied "P.sub.dynamic". Herein, a
symbol "N.sub.dynamic.sup.(RB)" denotes the number of resource
blocks of the entire system bandwidth, and symbols "N.sub.BCH",
"N.sub.SCH", "N.sub.PCH", "N.sub.RACHres", and "N.sub.persist"
denote the number of resource blocks allocated to the Broadcast
Channel (BCH), Synchronization signal, Paging Channel (PCH), RACH
response, and the downlink shared channel (DL-SCH) to which the
Persistent scheduling is applied, respectively in the
sub-frame.
N dynamie ( RB ) = min ( N system ( RB ) - N common - N persist , P
ma x - max ( P SCH , P BCH ) - P persist - P PCH - P RACHres P
dynamic ( RB ) ) N common = max ( N SCH , N BCH ) + N PCH + N
RACHres ( 6 ) ##EQU00004##
[0208] When an inequality
N.sub.dynamic.sup.(RB)<N.sub.system.sup.(RB)-N.sub.common-N.sub.persis-
tent is satisfied, the total transmission power value of the base
station apparatus 200 is controlled so that the total transmission
power value is equal to or less than the maximum transmission power
value of the base station apparatus 200 by preventing the
transmission using some RB group(s) among the RB groups other than
the RB groups allocated to the BCH, PCH, RACH response, and
downlink shared channel (DL-SCH) to which Persistent scheduling is
applied. More specifically, until the transmission of
"N.sub.system.sup.(RB)-N.sub.common-N.sub.persistent-N.sub.dynamic.sup.(R-
B)" or more resource blocks is prohibited, the following process is
performed to determine the RB group that is prevented from being
transmitted. In this process, first, a RB group having the smallest
number of resource blocks is detected and the transmission of the
detected RB group is prohibited. In this case, if more than two RB
groups having the smallest number of resource blocks exists, the
transmission of the RB groups is sequentially prohibited in the
ascending order of the RB group number. The above process is
repeated to sequentially determine the RB groups that are prevented
from being transmitted.
[0209] In step S408, a value of "k" is set to 1 (one) (k=1).
[0210] Next, in step S410, an RB Remaining Check process to
determine whether there are any remaining resource blocks is
performed.
[0211] More specifically, in step S410, it is determined whether
there is any remaining RB group that can be allocated to the
downlink shared channel (DL-SCH) to which Dynamic scheduling is
applied. When determining that there is an allocatable RB group,
the OK is returned. On the other hand, when determining that there
is no allocatable RB group, the NG is returned. When a result of
the RB Remaining Check is NG (NG in step S410), the DL TFR
Selection process is terminated.
[0212] The above-mentioned "RB group that can be allocated to the
downlink shared channel (DL-SCH) to which Dynamic scheduling is
applied" refers to an RB group other than the RB groups having been
allocated to any of BCH, PCH, RACH response, DL-SCH to which
Persistent scheduling is applied, and DL-SCH to which Dynamic
scheduling is applied and in which the TFR Selection process is
already performed. Further, the number of resource blocks included
in the "RB groups that can be applied to the downlink shared
channel (DL-SCH) to which Dynamic scheduling is applied" is defined
as N.sub.remain.sup.(RB).
[0213] In the above example, it is assumed that "RB group that can
be allocated to the downlink shared channel (DL-SCH) to which
Dynamic scheduling is applied" refers to an RB group other than the
RB groups having been allocated to any of BCH, PCH, RACH response,
DL-SCH to which Persistent scheduling is applied, and DL-SCH to
which Dynamic scheduling is applied and in which the TER Selection
process is already performed. However, alternatively, the "RB group
that can be allocated to the downlink shared channel (DL-SCH) to
which Dynamic scheduling is applied" may be an RB group other than
the RB groups having been allocated to any of Synchronization
signal, BCH, PCH, RACH response, DL-SCH to which Persistent
scheduling is applied, and DL-SCH to which Dynamic scheduling is
applied and in which the TFR Selection process is already
performed.
[0214] On the other hand, when the result of the RB Remaining Check
is OK (OK in step S410), the process goes to step S412.
[0215] Next, in step S412, the DL TFR Selection (Downlink TFR
Selection) process is performed.
[0216] More specifically, the transport format of "the user
equipment (UE) terminal in which radio resources are allocated
based on Dynamic scheduling (excluding PCH and RACH response)"
determined in step S212 is determined and the allocation of the RB
groups is performed.
[0217] In the DL TFR selection process, a CQI adjustment process is
performed. With respect to the CQI used in the TFR Selection
process, the following processes are applied; a frequency direction
regarding process, an Outer-loop type offset adjustment process,
and an offset process based on the priority level of the logical
channel having the Highest priority.
[0218] Next, the frequency direction regarding process is
described.
[0219] When the definition of the RB group of the CQI reported from
the user equipment (UE) terminal is different from the definition
of the RB group in the DL TFR Selection process, the CQI values of
the corresponding RB groups reported from the user equipment (UE)
(hereinafter referred to as CQI.sub.received(j); j denotes RB group
number) are regarded as the CQI values of the corresponding RB
groups in the DL TFR Selection process (hereinafter referred to as
CQI.sub.calibrated(i); i denotes RB group number). Further, when
Best-M individual method is used as a method of reporting the CQI
value, it is assumed that the CQI value for the RB group having no
CQI value is the same as the CQI value across the system bandwidth.
When the Best-M individual method is applied, for example, the
system bandwidth is divided into plural groups each having four
resource blocks, and CQI values with respect to each group of
resource blocks having four resource blocks are calculated, and top
M CQI values of higher quality are reported from the user equipment
to the base station apparatus.
[0220] In the following, when the CQI related to the entire system
bandwidth is expressed, the argument is described as "all".
[0221] For example, when N.sub.a resource blocks of the RB group #a
of the CQI reported from the user equipment (UE) and N.sub.I,
resource blocks of the RB group #b of the CWI reported from the
user equipment are included on RB group #i in the DL TFR Selection
process, the CQI value of RB group #i in the DL TFR Selection
process may be calculated based on the following formula.
CQI calibrated ( i ) = 10 log 10 ( N a 10 CQI received ( a ) 10 + N
b 10 CQI received ( b ) 10 N a + N b ) ( 7 ) ##EQU00005##
[0222] Next, the Outer-loop type offset adjustment process (CQI
offset adjustment) is described.
[0223] CQI_offset.sub.i is adjusted like an Outer loop as shown in
formula (8) based on the acknowledgement information (a result of
CRC check) of the downlink shared channel (DL-SCH) where the
priority class of the logical channel having the Highest priority
is X.sub.j,adjust. When the priority class of the logical channel
having the highest priority is other than X.sub.j,adjust, the
Outer-loop type offset adjustment process (in formula (8)) may not
be performed.
[0224] The CQI_offset, is adjusted with respect to each user
equipment (UE) terminal. Further, Priority class X.sub.j,adjust as
the target of the CQI offset adjustment process is set via the
external input interface (I/F) with respect to each user equipment
(UE) terminal.
[0225] .DELTA..sub.adj.sup.(PC) and BLER.sub.target.sup.(PC) may be
configured to be set via the external input interface (I/F).
However, it is assumed that the maximum value of CQI_offset.sub.i
is defined as CQI_offset.sub.PC.sup.(max), and the minimum value of
CQI_offset.sub.i is defined as CQI_offset.sub.PC.sup.(min). The
maximum value CQI_offset.sub.PC.sup.(max) and the minimum value
CQI_offset.sub.PC.sup.(min) of the CQI_offset.sub.i are set via the
external input interface (I/F). When the CQI_offset.sub.i is fixed
to the maximum value or the minimum value, the calculation of
formula (8) is not performed.
CQI_offset i = { CQI_offset i + .DELTA. adj ( PC X ) .times. BLER
target ( PC X ) Input = Ack '' '' CQI_offset i - .DELTA. adj ( PC X
) .times. ( 1 - BLER target ( PC X ) ) Input = Nack '' ''
CQI_offset i Input = DTX '' '' ( 8 ) ##EQU00006##
[0226] Then, the value of CQI_offset.sub.i is added to the value of
CQI of each RB group and a value of CQI related to the entire
system bandwidth as a power offset value. A process of the
following formula is performed with respect to each sub-frame in
which the DL TFR Selection process is performed regardless of
"whether the priority class of the logical channel having the
Highest priority is X.sub.j,adjust in the sub-frame".
CQI.sub.adjusted(i)=CQI.sub.adjusted(i)+CQI_offset.sub.i
[0227] Next, the offset process based on the priority level is
described.
[0228] The CQI values of the corresponding RB groups and the CQI
value related to the entire system bandwidth are adjusted using an
offset value .DELTA..sub.PC which is based on the priority level of
the logical channel having the Highest priority. The .DELTA..sub.PC
may be set via the external input interface (I/F). The subscriber
"pc" denotes Priority class.
CQI.sub.adjust(i)=CQI.sub.adjust(i)-.DELTA..sub.PC
[0229] Next, a resource block group allocation (RB group
allocation) is described. By performing the process below, the RB
group is allocated to kth user equipment (UE) terminal in which
radio resources are allocated based on the Dynamic Scheduling
(excluding PCH and RACH response). FIG. 6 schematically shows a
DL_TF_Related_table and a case where CQI=1 as an example.
Process
[0230] N.sub.remain.sup.(RB): the number of remaining resource
blocks (Number of Remaining RBs) [0231] N.sub.capability: the
maximum RB number determined based on UE category [0232]
N.sub.max,bit: the maximum data size (Payload size) determined
based on UE category
[0232] N remain ( UE ) = N DL - SCH - k + 1 N allocated ( RB ) =
min ( N remain ( RB ) N remain ( UE ) , N capability ) ( 9 )
##EQU00007##
[0233] When the downlink transmission type is Distributed, RB
groups are selected so that the allocated frequency resources can
be discretely distributed within the system bandwidth until the
number of the resource blocks allocated to the user equipment (UE)
terminal is equal to or greater than N.sub.allocated.sup.(UE). For
example, RB groups may be defined in advance so that when the RB
groups are sequentially allocated in the ascending order of the RB
group number, the allocated RB groups can be discretely
distributed; then the RB groups are sequentially allocated in the
ascending order of the RB group number to the user equipment (UE)
terminal.
[0234] When the downlink transmission type is not Distributed
(i.e., when the downlink transmission type is Localized), the RB
groups are sequentially allocated to the user equipment (UE)
terminal in the descending order of the value of CQI.sub.adjusted
of the RB groups until the number of the resource blocks allocated
to the user equipment (UE) terminal is equal to or greater than
N.sub.allocated.sup.(UE).
[0235] Hereinafter, the RB group determined "to be allocated to the
user equipment (DE) terminal" in the process describe above may be
referred to as a Temporary RB group.
[0236] In a case where the user equipment (UE) terminal has "the
logical channel for which the Persistent Resource is reserved in
step S338", the Persistent Resource is added to the Temporary RB
group.
[0237] When the logical channel having the Highest priority has
retransmittable data, data (MAC PDU) including RLC SDU having the
maximum "buffer residence time of the RLC SDU" of the logical
channel having the Highest priority are transmitted among the
retransmittable data (MAC PDU). Herein, the definition of the
buffer residence time of the RLC SDU is the same as that of the RLC
SDU buffer residence time described in No. 6 of Table 1. It is
assumed that the RB group used for the data transmission is the
same as the Temporary RB group; and the modulation scheme of the
data transmission is the same as that in the initial data
transmission.
[0238] On the other hand, when the logical channel having the
Highest priority does not have retransmittable data, CQI.sub.TFR is
calculated as follows.
[0239] When the downlink transmission type is Distributed, it is
given that CQI.sub.TFR=CQI.sub.adjusted (all). On the other hand,
when the downlink transmission type is not Distributed (i.e. when
the downlink transmission type is Localized),
CQI.sub.TFR=CQI.sub.adjusted (i) are true-value averaged across the
bandwidth of the Temporary RB group (the averaging is required to
be performed by considering (the difference of) the number of
resource blocks of each RB group).
[0240] The data size (DL-SCH) (hereinafter referred to as Size) and
the modulation scheme (hereinafter referred to as Modulation) of
the downlink shared channel (DL-SCH) are determined by referring to
a TF_related_table using the number of resource blocks in the
Temporary RB group (RB_available) and CQI.sub.TFR as arguments.
Size=DL_Table_TF_SIZE(RB_available,.left brkt-bot.CQI.sub.TFR.right
brkt-bot.)
Modulation=DL_Table_TF_Mod(RB_available,.left
brkt-bot.CQI.sub.TFR.right brkt-bot.) (10)
[0241] In a case of Size>N.sub.max,bit, a value of CQI.sub.TFR
is repeatedly reduced by 1 (one) until Size.ltoreq.N.sub.max,bit is
satisfied (refer to a Table of smaller CQI of a DL_TF_related
table, in this case, a value of RB_available is not changed). Based
on a confirmed value of Size, a value of Modulation is changed to a
value in accordance with the DL_TF_related_table.
[0242] Then, by the following procedure, the control information of
the MAC layer and data of all logical channels in a data buffer are
multiplexed with the MAC PDU having the above Size. Herein, the
data buffer may be, for example, an RLC buffer.
[0243] A case is described where there are plenty of data in the
RLC buffer.
[0244] Step 1: First, when there is the control information of the
MAC layer, the control information of the MAC layer is multiplexed
with the highest priority.
[0245] Step 2: Next, the data in the RLC buffer are sequentially
extracted from the logical channels in the descending order of the
priority level of the logical channel, and multiplexed. When there
are two or more logical channels having the same priority level, if
there are any DDCH, the DDCH is treated with the highest priority,
and if there is no DDCH, the data in the RLC buffer may be
sequentially extracted from the logical channels in any order. As a
method of selecting the logical channel in any order, a Round-Robin
method may be used.
[0246] Next, a case is described where there are no sufficient data
in the RLC buffer.
[0247] The number of resource blocks to be allocated NUM.sub.RB is
recalculated by referring to the TF_related_table using the total
size Size.sub.all of data in the MAC control block and the RLC
buffer of all logical channels and CQI.sub.TFR as arguments
Num.sub.RB=DL_Table_TF_RB(Size.sub.all,.left
brkt-bot.CQI.sub.TFR.right brkt-bot.) (11)
[0248] When the downlink transmission type is Distributed, RB
groups in the Temporary RB group are removed by repeating a process
in which the RB group having the least number of resource blocks is
removed, or when there are two or more RB groups having the same
least number of resource blocks, the RB groups are sequentially
removed in the ascending order of the RB group number as long as
the number of resource blocks to be used for transmission is equal
to or greater than NUM.sub.RB (removed RB groups are used as
(k+1)th radio resource or later of the user equipment (UE)). The
number of resource blocks in the Temporary RB group after the
process is performed is defined as Num.sub.RB,F.
[0249] When the downlink transmission type is not Distributed, RB
groups in the Temporary RB group are removed by repeating a process
in which the RB group having the least value of CQI.sub.adjusted is
removed, or when there are two or more RB groups having the same
least value of CQI.sub.adjusted, the RB groups are sequentially
removed in the ascending order of the number of resource blocks
included in the RB groups, or when there are two or more RB groups
having the same least value of CQI.sub.adjusted and the same least
number of resource blocks, the RB groups are sequentially removed
in the descending order of the RB group number as long as the
number of resource blocks to be used for transmission is equal to
or greater than NUM.sub.RB.
[0250] The RB groups removed in the above process are used as
(k+1)th radio resource or later. The number of resource blocks in
the Temporary RB group after the process is performed is defined as
Num.sub.RB,F.
Size=DL_Table_TF_SIZE(Num.sub.RB,F,.left brkt-bot.CQI.sub.TFR.right
brkt-bot.)
Modulation=DL_Table_TF_Mod(Num.sub.RB,F,.left
brkt-bot.CQI.sub.TFR.right brkt-bot.) (12)
[0251] Next, an RV Selection (Redundancy Version Selection) process
in step S414 is described.
[0252] The RV parameter in each retransmission time (a value which
is zero (0) in the initial transmission) is set via the external
input interface (I/F). The base station apparatus (eNB) 200
determines the value of the RV parameter based on the value of RSN.
The RSN is set based on the estimated number of receiving the MAC
PDU. Namely the RSN is set based on the number of NACK of the
HARQ-ACK for DL-SCH which is the acknowledgement information of the
downlink shared channel (DL-SCH) received in Uplink (when a result
of the ACK/NACK/DTX determination result of the HARQ-ACK for DL-SCH
is DTX, a value of RSN is not incremented).
[0253] In step S416, the value of k is incremented. In step S418,
it is determined whether the value of k is equal to or less than
N.sub.DL-SCH. When determining that the value of k is equal to or
less than N.sub.DL-SCH (YES in step S418), the process goes back to
step S410. On the other hand, when determining that the value of k
is not equal to or less than N.sub.DL-SCH (NO in step S418), the
process is terminated.
[0254] Next, the base station apparatus 200 according to an
embodiment of the present invention is described with reference to
FIG. 7.
[0255] As shown in FIG. 7, the base station apparatus 200 according
to an embodiment of the present invention includes a PCH RACH
response detection section 204, a scheduling coefficient
calculation section 206 (as a selection unit), a transport
format/resource block selection section 210 (as an allocation
section), and a layer 1 processing section 212.
[0256] The PCH RACH response detection section 204 performs the
process of step S206 described above. Specifically, the PCH RACH
response detection section 204 counts the numbers of PCH and RACH
response in the sub-frame and reports the results (counted numbers)
to the scheduling coefficient calculation section 206.
[0257] The scheduling coefficient calculation section 206 performs
the process of step S208. Specifically, the scheduling coefficient
calculation section 206 selects user equipment (UE) terminals to
which the radio resources are allocated based on the Dynamic
scheduling in the sub-frame and reports the number "N.sub.DL-SCH"
of user equipment (UE) terminals to which the radio resources are
allocated based on the Dynamic scheduling to the transport
format/resource block selection section 210.
[0258] The transport format/resource block selection section 210
performs the process of steps S212 and S214. Specifically, the
transport format/resource block selection section 210 performs
downlink transport format and resource selection. More
specifically, the transport format/resource block selection section
210 determines transmission formats and allocates radio resources
related to common channels such as the Synchronization channel
(SCH), the Broadcast Channel (BCH), the Paging Channel (PCH), and
the Random Access Channel (RACH) response (RACH response), the
Downlink Shared Channel (DL-SCH) to which the Persistent Scheduling
is applied, and the Downlink Shared Channel (DL-SCH) to which the
Dynamic Scheduling is applied.
[0259] The layer 1 processing section 212 performs a process
related to the layer 1.
[0260] Next, a user equipment (UE) terminal 100.sub.n is described
with reference to FIG. 8.
[0261] As shown in FIG. 8, the user equipment (UE) terminal
100.sub.n includes a transmission/receiving antenna 102, an
amplifier 104, a transmission/receiving section 106, a baseband
signal processing section 108, and an application section 110.
[0262] Regarding downlink data, a radio-frequency signal received
by the transmission/receiving antenna 102 is amplified in the
amplifier 104 and frequency-converted into a baseband signal in the
transmission/receiving section 106. This baseband signal is FFT
processed and reception processed such as error correction decoded
and retransmission controlled in the baseband signal processing
section 108. Downlink user data of the downlink data are
transmitted to the application section 110. The application section
110 performs, for example, processes related to a layer higher than
the physical layer or the MAC layer.
[0263] In this case, when the system bandwidth is 5 MHz, the
baseband signal processing section 108 may have a capability of
receiving Broadcast Channel (BCH) as shown in FIG. 5. Namely the
baseband signal processing section 108 may have a capability of
receiving the Broadcast Channel (BCH) (CCPCH as a Physical Channel)
mapped to sub-carriers shifted from the resource blocks to which
downlink shared channel (DL-SCH) is mapped by 90 kHz (6
sub-carriers).
[0264] On the other hand, uplink data are transmitted from the
application section 110 to the baseband signal processing section
108. The baseband signal processing section 108 performs a
transmission process of retransmission control (H-ARQ (Hybrid
ARQ)), channel coding, an IFFT process and the like on the user
data and outputs the user data to the transmission/receiving
section 106. The transmission/receiving section 106 performs a
frequency conversion to convert the baseband signal output from the
baseband signal processing section 108 into a signal in radio
frequency band. The signal is amplified in the amplifier 104 and
transmitted from the transmission/receiving antenna 102.
Second Embodiment
[0265] A radio communication system having a base station apparatus
according to this embodiment of the present invention is applied is
similar to that described with reference to FIG. 1.
[0266] Similar to the first embodiment of the present invention
described above, as shown in FIG. 1, the radio communication system
1000, which may be an Evolved UTRA (Universal Terrestrial Radio
Access) and UTRAN (UTRA Network) system (a.k.a an LTE (Long Term
Evolution) system or a super 3G system), includes a base station
apparatus (eNB: eNode B) 200 and plural user equipment (UE)
100.sub.n (100.sub.1, 100.sub.2, 100.sub.3, . . . 100.sub.n; n: an
integer greater than zero (0)) (hereinafter, the user equipment
(UE) may be referred to as a user equipment terminal(s)). The base
station apparatus 200 is connected to an upper node station such as
an access gateway apparatus 300. The access gateway apparatus 300
is connected to a core network 400. In this case, the user
equipment (UE) terminals 100.sub.n are in communication with the
base station apparatus 200 in a cell 50 based on the Evolved UTRA
and UTRAN radio communication scheme.
[0267] Each of the user equipment terminals (100.sub.1, 100.sub.2,
100.sub.3, . . . 100.sub.n) has the same configuration, functions,
and status. Therefore, unless otherwise described, the term user
equipment (UE) 100.sub.n may be collectively used in the following
descriptions.
[0268] As the radio access scheme in the radio communication system
1000, the OFDM (Orthogonal Frequency Division Multiplexing) scheme
and the SC-FDMA (Single-Carrier Frequency Division Multiplexing
Access) scheme are used in downlink and uplink communications,
respectively. As described above, the OFDM scheme is a
multi-carrier transmission scheme in which a frequency band is
divided into plural sub-carriers having narrow frequency bands and
data are mapped on each sub-carrier to be transmitted. The SC-FDMA
scheme is a single-carrier transmission scheme in which a frequency
band is divided so that different frequencies can be used among
plural terminals and as a result, interferences between terminals
can be reduced.
[0269] Next, communication channels used in the Evolved UTRA and
UTRAN radio communication scheme are described.
[0270] In downlink communications, a Physical
[0271] Downlink Shared Channel (PDSCH) that is shared among the
user equipment terminals 100.sub.n and a Physical Downlink Control
Channel (PDCCH) are used. In downlink, user information and
transport format information of a Downlink Shared Channel, the user
information and the transport information of an Uplink Shared
Channel, acknowledgement information of the Uplink Shared Channel
and the like are reported via the Physical Downlink Control Channel
(PDCCH). User data are transmitted via the Physical Downlink Shared
Channel (PDSCH). The user data are transmitted via a Downlink
Shared Channel (DL-SCH) as a transport channel.
[0272] In uplink communication, a Physical Uplink Shared Channel
(PUSCH) that is shared among user equipment terminals 100, and an
LTE control channel are used. The LTE control channel has two
types, one is to be time domain multiplexed with the Physical
Uplink Shared Channel (PUSCH) and the other is to be frequency
domain multiplexed with the Physical Uplink Shared Channel (PUSCH).
The control channel to be frequency domain multiplexed with the
Physical Uplink Shared Channel (PUSCH) is called a Physical Uplink
Control Channel (PDCCH).
[0273] In uplink communication, a downlink Channel Quality
Indicator (CQI) to be used for scheduling in downlink and an
Adaptive Modulation and Coding (AMC) and acknowledgement
information of the Downlink Shared Channel (HARQ (Hybrid Automatic
Repeat reQuest) ACK information) are transmitted via the LTE
control channel. Further, the user data are transmitted via the
Physical Uplink Shared Channel (PUSCH). The user data are
transmitted via an Uplink Shared Channel (UL-SCH) as a transport
channel.
[0274] Next, a Downlink MAC (DL MAC) data transmission procedure as
a communication control method performed in a base station
apparatus according an embodiment of the present invention is
described.
[0275] In this embodiment, a logical channel corresponds to, for
example, a Radio bearer; and a Priority class corresponds to, for
example, a priority level or Logical Channel Priority.
[0276] Next, an allocation unit of the transmission bandwidth of
the Physical Downlink Shared Channel (PDSCH) is described. The
allocation of the Physical Downlink Shared Channel (PDSCH) is
performed with respect to each sub-frame by treating, for example,
a Resource block group (hereinafter may be referred to as RB group)
as a unit, the RB group being defined as a system parameter. Each
RB group includes plural Resource Blocks (RBs), and a corresponding
relationship between the RBs and the RB group is set as a system
parameter via an external input interface (I/F). The relationship
between the resource blocks and the RB group is treated as a system
parameter; however the relationship may be specified using a fixed
parameter in the apparatus. The allocation of the transmission
bandwidth by treating the RB group as a unit may also be performed
on the Physical Downlink Shared Channel (PDSCH) to which Persistent
scheduling is applied. In the following, a case is described where
the RB group is configured. However, without configuring the RB
block, the allocation of the Physical Downlink Shared Channel
(PDSCH) may be performed by treating the resource block as a
unit.
[0277] Further, in the descriptions below, a dynamic scheduling
corresponds to a first resource allocation method of dynamically
allocating radio resources. When the dynamic scheduling is applied
to the Downlink Shared Channel (DL-SCH), radio resources are
allocated to arbitrary sub-frames with respect to the user
equipment (UE). Further, in this case, various values may be set as
the values of the transmission format including the allocation
information of the resource blocks as frequency resources,
modulation scheme, payload size, HARQ information items, such as a
Redundancy version parameter, a process number and the like, and
information items of an MIMO and the like. The transmission format,
i.e., allocation information of the resource blocks as frequency
resources, modulation scheme, payload size, HARQ information items,
such as a Redundancy version parameter, a process number and the
like, and information items of an MIMO and the like, is reported to
the user equipment (UE) terminal using DL scheduling information
mapped to the physical downlink control channel (PDCCH).
[0278] On the other hand, the Persistent scheduling is a scheduling
method of allocating transmission opportunities at a predetermined
cycle in accordance with a type of data or features of the
application to transmit/receive data and corresponds to a second
resource allocation method of allocating radio resources at the
predetermined cycle. Namely, when the Persistent scheduling is
applied to the Downlink Shared Channel (DL-SCH), the Downlink
Shared Channel (DL-SCH) is transmitted using predetermined
sub-frames with respect to the user equipment (UE). Further, in
this case, predetermined values are set as the values of the
transmission format including the allocation information of the
resource blocks as frequency resources, modulation scheme, payload
size, HARQ information items, such as the Redundancy version
parameter, the process number and the like, and the information
items of the MIMO and the like. Namely, the shared channel (radio
resource) is allocated to the predetermined sub-frames, and the
Downlink Shared Channel (DL-SCH) is transmitted using the
predetermined transmission format. In this case, the predetermined
sub-frames may be arranged, for example, at a predetermined cycle.
Further, the predetermined transmission format is not necessarily
fixed to one type, and so, plural types of transmission formats may
be provided.
[0279] Next, a downlink MAC data transmission procedure is
described with reference to FIG. 9. FIG. 9 shows a procedure from a
scheduling process by calculating scheduling coefficients to a DL
TFR selection process of determining the transport format and the
RB group to be allocated.
[0280] As shown in FIG. 9, in step S902, a DL MAC maximum
multiplexing number N.sub.DLMAX is set in the base station
apparatus 200. The DL MAC maximum multiplexing number N.sub.DLMAX
is the maximum multiplexing number in one sub-frame of the Downlink
Shared Channel (DL-SCH) to which the Dynamic Scheduling is applied
and is designated via the external input interface (I/F). Further,
the DL MAC maximum multiplexing number N.sub.DLMAX may be the
maximum number of the Downlink Scheduling Information transmitted
in one sub-frame.
[0281] Next, in step S904, the base station apparatus 200 counts
the number of MCHs (MCH number) in the sub-frame and defines the
numbers as N.sub.MCH. In this case, instead of using actual MCH
number, the number of Downlink Scheduling Information for the MCH
may be calculated as the MCH number.
[0282] Next, in step S906, the numbers of PCH, RACH response,
D-BCH, and RACH message4 are counted, and the counted numbers are
defined as N.sub.PCH, N.sub.RACHres, N.sub.D-BCH, and N.sub.RACHm4,
respectively. In this case, however, as the numbers of the PCH,
RACH response, D-BCH, and RACH message4, the number of Downlink
Scheduling information for the PCH, the number of Downlink
Scheduling information for the RACH response, the number of
Downlink Scheduling information for the D-BCH, the number of
Downlink Scheduling information for the RACH message4, respectively
may be used. Further, in this process, with respect to the PCH,
RACH response, D-BCH, and RACH message4, the numbers of the PCH,
RACH response, D-BCH, and RACH message4 are counted. However,
alternatively, only some of the PCH, RACH response, D-BCH, and RACH
message4 may be counted, or a common channel other than the PCH,
RACH response, D-BCH, and RACH message4 may similarly be counted,
or a common channel other then any of the above channels may
similarly be counted.
[0283] Next, in step S908, a calculation of scheduling coefficients
is performed in the base station apparatus 200. In this step, the
user equipment (UE) terminals in which radio resources are
allocated based on the Dynamic scheduling in the sub-frame are
selected. The number of user equipment (UE) terminals in which the
radio resources are allocated based on the Dynamic scheduling in
the sub-frame is defined as N.sub.DL-SCH.
[0284] Next, in step S912, a Downlink Transport format and Resource
selection (DL TFR) is performed. Namely, transmission formats are
determined and the radio resources are allocated with respect to
each of a Synchronization signal (also called a Synchronization
Channel (SCH)), a Primary Broadcast Channel (P-BCH), a Dynamic
Broadcast Channel (D-BCH), a Paging Channel (PCH), a Random Access
Channel (RACH) response (RACH response, or message2 in random
access procedure), the Downlink Shared Channel (DL-SCH) to which
MCH and the Persistent Scheduling is applied, and the Downlink
Shared Channel (DL-SCH) to which the Dynamic Scheduling is
applied.
[0285] Next, the Calculation for Scheduling coefficients performed
in step S908 is described with reference to FIG. 10.
[0286] FIG. 10 shows a process of selecting the user equipment (UE)
terminal(s) in which radio resources are allocated based on the
Dynamic scheduling by calculating the Scheduling coefficients. The
base station apparatus 200 performs the following processes with
respect to all the user equipment (UE) terminals in the LTE active
state including, for example, in the RRC (Radio Resource Control)
connecting state.
[0287] As shown in FIG. 10, in step S1002, formulas of n=1 and
N.sub.scheduling=0 are provided; where n denotes an index of the
user equipment terminals 100.sub.n and n=1, . . . , N (N is an
integer greater than 0).
[0288] Next, in step S1004, Renewal of HARQ (Hybrid Automatic
Repeat reQuest) Entity Status is performed. In this step, in the
user equipment (UE), a process receiving ACK as the acknowledgement
information with respect to the Downlink Shared Channel (DL-SCH) is
released. Further, a process in which the maximum number of
retransmissions has been reached is also released and the user data
in the process are discarded. The maximum number of retransmissions
is set with respect to each Priority class via the external input
interface (I/F). Further, it is assumed that the maximum number of
retransmissions of MAC PDU (Protocol Data Unit), in which plural
logical channels are multiplexed, complies with the maximum number
of retransmissions of a logical channel having the highest Priority
Class.
[0289] Next, in step S1006, a Measurement Gap Check is performed.
More specifically, it is determined whether the sub-frame (i.e.,
the sub-frame transmitting the Downlink Shared Channel (DL-SCH)) is
included in the Measurement Gap or whether the sub-frame receiving
the acknowledgement information (ACK/NACK) with respect to the
Downlink Shared Channel (DL-SCH) is included in the Measurement
Gap. When determining that the sub-frame is included in the
Measurement Gap or that the sub-frame receiving the acknowledgement
information (ACK/NACK) is included in the Measurement Gap, an NG
(signal) is returned, otherwise, an OK (signal) is returned. The
Measurement Gap refers to a time interval when cells operating at a
different frequency are measured for a different-frequency handover
of the user equipment (UE), and during the time interval,
communications cannot be performed and therefore, the user
equipment (UE) cannot receive the Downlink Shared Channel (DL-SCH).
Further, during the time period when measuring the cell operating
at a different frequency, the user equipment (UE) cannot transmit
the acknowledgement information (ACK/NACK). As a result, the base
station apparatus 200 cannot receive the acknowledgement
information (ACK/NACK). Accordingly, when a result of the
Measurement Gap Check is NG (NG in step S1006), the user equipment
(UE) terminal is excluded from a target of the scheduling
process.
[0290] In this case, the cell operating at a different frequency
may be a cell of the Evolved UTRA and UTRAN system or a cell of
another system such as, for example, GSM, WCDMA, TDD-CDMA, CDMA
2000, or WiMAX system.
[0291] When determining that a result of the Measurement Gap Check
is OK (OK in step S1006), the process goes to step S1007 in which a
Half Duplex Check is performed. The Half Duplex refers to a
communication method in which uplink transmission and downlink
transmission are not performed simultaneously. In other words, in
the Half Duplex, uplink transmission and downlink transmission are
performed at different timings.
[0292] In the Half Duplex Check process, when the user equipment
(UE) terminal performs the Half Duplex communication, the following
six (6) determinations (D1 through D6 described below) may be made
and if at least one result is YES (correct) among the six
determinations, the NG may be returned, otherwise, the OK may be
returned.
[0293] D1: whether the subframe, i.e., the sub-frame to transmit
the downlink shared channel (DL-SCH), overlaps the sub-frame to
transmit uplink shared channel (UL-SCH) in the user equipment (UE)
terminal.
[0294] D2: whether the subframe, i.e., the sub-frame to transmit
the downlink shared channel (DL-SCH), overlaps the sub-frame to
transmit at least one of CQI (downlink radio quality information),
a Sounding Reference Signal, a Scheduling Request (signal), and
Random Access Channel (RACE) in the user equipment (UE)
terminal.
[0295] D3: whether the subframe, i.e., the sub-frame to transmit
the downlink shared channel (DL-SCH), overlaps the sub-frame to
transmit the acknowledgement information (ACK/NACK) with respect to
the downlink shared channel (DL-SCH) in the uplink of the user
equipment (UE) terminal.
[0296] D4: when downlink shared channel (DL-SCH) is transmitted via
the sub-frame, whether the sub-frame to transmit the
acknowledgement information (ACK/NACK) with respect to the downlink
shared channel (DL-SCH) in the uplink of the user equipment (UE)
terminal overlaps the sub-frame to transmit the downlink shared
channel (Synchronization Channel (SCH))/Primary Broadcast Channel
(P-BCH)/Dynamic Broadcast Channel (D-BCH)/MBMS channel.
[0297] D5: when downlink shared channel (DL-SCH) is transmitted via
the sub-frame, whether the sub-frame to transmit the
acknowledgement information (ACK/NACK) with respect to the downlink
shared channel (DL-SCH) in the uplink of the user equipment (UE)
terminal overlaps the sub-frame to transmit the acknowledgement
information (ACK/NACK) with respect to the uplink shared channel
(DL-SCH) transmitted from the user equipment (UE) terminal
before.
[0298] D6: when downlink shared channel (DL-SCH) is transmitted via
the sub-frame, whether the sub-frame to transmit the
acknowledgement information (ACK/NACK) with respect to the downlink
shared channel (DL-SCH) in the uplink of the user equipment (UE)
terminal overlaps the sub-frame to transmit the control information
(Uplink Scheduling Grant and Downlink Scheduling Information) for
uplink or downlink Persistent Scheduling.
[0299] Further, regarding the uplink and downlink channels relevant
to the determinations, all of the corresponding channels may be
considered, or only some of the corresponding channels may be
considered. When a result of the Half Duplex Check process is NG
(NG in step S1007), the user equipment (UE) terminal is excluded
from a target of the scheduling process.
[0300] As described above, upon performing uplink transmission, the
user equipment (UE) terminal in Half Duplex cannot perform downlink
transmission. Therefore, by doing the process described above,
namely by determining whether uplink transmission is to be
performed in the sub-frame and performing a process not to transmit
the downlink transmission, it may become possible to avoid the
problem that the user equipment (UE) terminal in Half Duplex cannot
receive a downlink transmission signal upon performing uplink
transmission.
[0301] Further, in the six determinations described above, each
determination may be made by considering a switching period
required to switch between downlink reception and uplink
transmission in the user equipment (UE) terminal. More
specifically, for example, when the transmission timing of the
acknowledgement information with respect to the downlink shared
channel (DL-SCH) in the user equipment (UE) terminal or the
transmission timing of the downlink shared channel (DL-SCH) in the
base station apparatus overlaps the switching timing, the result of
the Half Duplex Check process may be determined as "NG".
[0302] In the above example, the Half Duplex Check process is
performed with respect to the user equipment (UE) terminal to
communicate in Half Duplex mode. However, the Half Duplex Check
process may be performed with respect to not only the user
equipment (UE) terminal to communicate in Half Duplex mode but also
the user equipment (UE) terminal to communicate in Full Duplex
mode. Further, the Half Duplex Check process may be performed with
respect to all the user equipment (UE) terminals to communicate in
Full Duplex mode. Otherwise, the Half Duplex Check process may be
performed with respect to the user equipment (UE) terminal
communicating in Full Duplex mode and having a value of path loss
between the user equipment (UE) terminal and the base station
apparatus 200 greater than a threshold value; and, on the other
hand, the Half Duplex Check process may not be performed with
respect to the user equipment (UE) terminal communicating in Full
Duplex mode and having a value of path loss between the user
equipment (UE) terminal and the base station apparatus 200 less
than the threshold value. In this case, uplink transmission and
downlink transmission are not performed at the same time;
therefore, it may become possible to avoid a problem that "uplink
transmission signal in the user equipment (UE) terminal acts as an
interference signal to a downlink receiving signal; and as a
result, quality of downlink receiving signal is degraded" described
below. Further, the Half Duplex Check process may be performed with
respect to a user equipment (UE) terminal to communicate in Full
Duplex mode in a cell or a frequency band which may be heavily
influenced by the problem that "uplink transmission signal in the
user equipment (UE) terminal acts as an interference signal to a
downlink receiving signal; and as a result, quality of downlink
receiving signal is degraded"; and on the other hand, the Half
Duplex Check process may not be performed with respect to a user
equipment (UE) terminal to communicate in Full Duplex mode in a
cell or a frequency band which may not be heavily influenced by the
problem that "uplink transmission signal in the user equipment (UE)
terminal acts as an interference signal to a downlink receiving
signal; and as a result, quality of downlink receiving signal is
degraded".
[0303] When a result of the Half Duplex Check process is OK (OK in
step S1007), the process goes to step S1008 in which a
Discontinuous Reception (DRX) Check process is performed. In step
S1008, it is determined whether the user equipment (UE) is in DRX
(Discontinuous Reception) mode. When determining that the user
equipment (UE) is in DRX mode, it is further determined whether the
sub-frame is included in a DRX reception timing. When determining
that the user equipment (UE) is in DRX (Discontinuous Reception)
mode and the sub-frame is not included in the DRX reception timing,
the "NG" is returned, otherwise the "OK" is returned. Namely when
determining that "the user equipment (UE) is not in DRX mode" or
that "the user equipment (UE) is in DRX mode and the sub-frame is
included in the DRX reception timing", the OK is returned. Further,
"in a case of not being in DRX mode", a value of flag.sub.DRX
described below is set to 0 (zero); and "in a case of being in DRX
mode and in DRX reception timing", the value of flag.sub.DRX is set
to 1 (one). Herein, the DRX reception timing refers to a timing
when data can be received during DRX mode. The DRX reception timing
may also be called "On-duration". Further, when a state is in DRX
mode and not in the DRX reception timing, the state corresponds to
a sleep mode in which no downlink signal is to be received.
[0304] Further, when a state is in DRX mode and in a retransmission
timing of the data transmitted via the Persistent resource (i.e.,
"Sub-frame of initial transmission+HARQ RTT".about."Sub-frame of
initial transmission+HARQ RTT+DRX Retransmission Timer"), the state
may be regarded as the state in DRX mode and the DRX reception
timing. Herein, the "DRX Retransmission Timer" refers to a
parameter indicating a section when retransmission with respect to
the initial transmission may be performed and the parameter is set
in advance between the base station apparatus and the user
equipment (UE) terminal. Further, in the above example, the DRX
Retransmission Timer is limited to the initial transmission.
However, the DRX Retransmission Timer may be applied to a
transmission other than the initial transmission. Further, the
value of the HARQ RTT may be, for example, 8 sub-frames; otherwise,
the value of the DRX Retransmission Timer may be, for example, 3
sub-frames. However, the values of 8 sub-frames and 3 sub-frames
are examples only, and other values may also be applied.
[0305] When a result of the DRX Check process is NG (NG in step
S1008), the user equipment (UE) terminal is excluded from a target
of the scheduling process.
[0306] On the other hand, when the result of the DRX Check process
is OK (OK in step S1008), the process goes to step S1010 in which a
Received CQI (Channel Quality Indicator) Check process is
performed. Namely, a value of CQI used in the sub-frame is
obtained. For example, in a case where the base station apparatus
200 has ever received at least one CQI in the past from the user
equipment (UE) terminal, the latest CQI across the system bandwidth
(Wideband CQI) and a UE Selected Sub-band CQI are used in a process
of step S1024 described below and the process in step S912.
Further, for example, in a case where the base station apparatus
200 has never received--not even once--CQI from the user equipment
(UE) terminal in the past, the CQI is set via the external input
interface (I/F); namely a predetermined fixed CQI across the system
bandwidth (Wideband CQI) is used in the process of step S1024 and
the process of step S912. Further, the predetermined fixed CQI
across the system bandwidth (Wideband CQI) may be, for example,
stored as a parameter in the apparatus. Further, the predetermined
fixed CQI across the system bandwidth (Wideband CQI) set via the
external input interface (I/F) may be calculated based on received
SIR of the user equipment (UE) terminal located at an edge portion
of the cell.
[0307] Further, the base station apparatus 200 may determine the
reliability of received CQI; and when determining that the
reliability is low, the received CQI may be regarded as
not-received. Namely the phrase "has ever received at least one CQI
in the past" may be regarded as "has ever received at least one
sufficiently reliable CQI in the past". Otherwise, the phrase
"latest CQI across the system bandwidth (Wideband CQI) and a UE
Selected Sub-band CQI" may be regarded as "among sufficiently
reliable CQI, latest CQI across the system bandwidth (Wideband CQI)
and a UE Selected Sub-band CQI". Otherwise, the term "has never
received--not even once--CQI" may be regarded as "has never
received--not even once--any sufficiently reliable CQI". Further,
the reliability of received CQI may be determined based on, for
example, the received quality of CQI such as the SIR of CQI signal
and more specifically based on the SIR of a Demodulation Reference
Signal. Namely when the received quality value of the CQI is equal
to or greater than a predetermined threshold value, it may be
determined that the reliability of the CQI is high; and when the
received quality value of the CQI is less than the predetermined
threshold value, it may be determined that the reliability of the
CQI is low.
[0308] In step S1012, it is determined whether, in the sub-frame,
the Persistent Resource is allocated to the user equipment
terminal. Herein, the Persistent Resource refers to a Resource
block reserved for the Persistent Scheduling. The Persistent
scheduling is a scheduling method of allocating transmission
opportunities at a predetermined cycle in accordance with a type of
data or features of the application to transmit/receive data.
Further, the type of data may include data of Voice Over IP,
Streaming data or the like. The Voice Over IP and the Streaming
data correspond to the applications.
[0309] Herein, the Persistent Resource may be a resource allocated
for the initial transmission of the HARQ. In this case, when the
data are retransmitted, the data are transmitted as the downlink
shared channel (DL-SCH) to which the Dynamic Scheduling is applied.
Namely regarding the retransmission of the data, the transmission
is performed by selecting the user equipment (UE) terminal to
transmit the data based on a UE selection process of S1032
described below.
[0310] When determining that the Persistent resource is to be
allocated (OK in step S1012), the process goes to step S1014 in
which a Data Size Check process is performed. When determining that
the Persistent resource is not to be allocated (NG in step S1012),
the process goes to step S1020 in which the Localized/Distributed
Check process is performed. In localized (transmission), it may be
advantageous to allocate relatively consecutive frequency blocks
(resource blocks) based on CQI because a fading frequency in a
propagation environment between the user equipment (UE) and the
base station apparatus 200 is (relatively) small. On the other
hand, in Distributed (transmission), it may be advantageous to
allocate frequency blocks (resource blocks) which are relatively
discretely distributed (separated) from each other regardless of
the CQI values because the fading frequency in a propagation
environment between the user equipment (UE) and the base station
apparatus 200 is (relatively) large. Further, the term "Localized"
may also be called "Low Fd" (Fd: Fading frequency) and the term
"Distributed" may also be called "High Fd" (Fd: Fading
frequency).
[0311] In step S1014, it is determined whether a size of the
transmittable data of the logical channel of the user equipment is
equal to or greater than a threshold value
Threshold.sub.data.sub.--.sub.size, the Persistent scheduling being
applied to the logical channel. When determining that the size of
the transmittable data is equal to or greater than the threshold
value Threshold.sub.data.sub.--.sub.size (NG in step S1014), the
process goes to step S1018 in which the Persistent Resource Release
process is performed. On the other hand, when determining that the
size of the transmittable data is less than the threshold value
Threshold.sub.data.sub.--.sub.size (OK in step S1014), the process
goes to step S1016 in which a Persistent Resource Reservation
process is performed. In this case, it may be set in advance
whether the Persistent Scheduling is applied to each logical
channel. For example, it may be determined that the Persistent
Scheduling is applied to a logical channel transmitting VoIP data
and the Dynamic Scheduling is applied to the other logical
channels.
[0312] Further, as the threshold value
Threshold.sub.data.sub.--.sub.size, for example, the maximum value
that can be transmitted by the Persistent resource may be set.
[0313] In step S1016, the Persistent Resource to be allocated to
the logical channel of the user equipment (UE) is reserved, the
Persistest scheduling being applied to the logical channel.
Further, the calculation of the scheduling coefficients described
below is also performed with respect to the user equipment (UE)
terminal to which the Persistent Resource is applied in the
sub-frame. Further, when the radio resources are allocated to the
logical channel to which the Dynamic Scheduling is applied in the
sub-frame, the Persistent Resources are released, and the logical
channel to which the Persistent scheduling is applied and the
logical channel to which the Dynamic scheduling is applied are
multiplexed with the Resource applied for the logical channel to
which the Dynamic scheduling is applied, so that the MAC PDU
(DL-SCH) is transmitted.
[0314] Further, the calculation of the scheduling coefficients in
step S1024 described below is also performed with respect to the
user equipment (UE) terminal to which the Persistent Resource is
applied in the sub-frame. Further, when transmission resources are
allocated for the logical channel to which the Dynamic Scheduling
is applied in the sub-frame, the Persistent Resources are released,
and the MAC PDU (DL-SCH) is transmitted to the user equipment (UE)
terminal by using the Resource allocated for the logical channel to
which the Dynamic scheduling is applied. The method of multiplexing
the data in the RLC buffer of the MAC control block and each
logical channel with the MAC PDU is shown in step S912.
[0315] Herein, the MAC control block refers to control information
of the MAC layer; otherwise, the MAC control block may be header
information of the MAC layer.
[0316] In step S1018, the Persistent Resources to be allocated to
the logical channel of the user equipment (UE) terminal are
released, the Persistent scheduling being applied to the logical
channel. In this case, with respect to the Persistent Resources, it
is assumed that only the sub-frame is released; and at the next
timing when the next Persistent Resource is allocated, the Data
Size Check process (in step S1014) is to be performed again.
[0317] In step S1020, the downlink transmission type (DL
Transmission type) of the user equipment (UE) terminal is
determined. Namely, it is determined whether the downlink
transmission type is Localized (transmission) or Distributed
(transmission). Further, the transmission type may be commonly
managed with respect to both downlink transmission and uplink
transmission.
[0318] For example, when the Fd estimation value of the user
equipment (UE) terminal is equal to or less than the threshold
value Threshold.sub.Fd,DL, it is determined that the transmission
type is Localized (transmission). Otherwise, it is determined that
the transmission type is Distributed (transmission). As described
above, the Localized transmission may also be called Low Fd, and
the Distributed transmission may also be called High Fd.
[0319] As the Fd estimation value, a value reported in the RRC
message such as the Measurement report from the user equipment (UE)
terminal or a value calculated based on a time correlation value of
the Sounding reference signal transmitted from the user equipment
(UE) terminal may also be used. Otherwise, the Fd estimation value
may be calculated based on the time correlation value of the
Demodulation Reference Signal in the Physical Uplink Shared Channel
(PUSCH) transmitted from the user equipment (UE) terminal.
Otherwise, the Fd estimation value may be calculated based on the
time correlation value of the Demodulation Reference Signal in the
Physical Uplink Control Channel (PUCCH) transmitted from the user
equipment (UE) terminal. Via the Physical Uplink Control Channel
(PUCCH), the acknowledgement information with respect to the
downlink shared channel (DL-SCH) and the downlink quality
information (CQI(Channel Quality Indicator)) are transmitted.
[0320] Next, in step S1022, a Buffer Status Check is performed.
More specifically, with respect to the logical channel of the user
equipment (UE), it is determined whether there are transmittable
data in the sub-frame. Namely the base station apparatus 200
determines whether there are transmittable data in the data buffer
with respect to each logical channel of the user equipment (UE).
When determining that there are no transmittable data in any of the
logical channels, the NG is returned. On the other hand, when
determining that there are transmittable data in at least one
logical channel, the OK is returned. Herein, the transmittable data
includes the data that can be newly transmitted or the data that
can be retransmitted.
[0321] However, in the following, exceptional processes in checking
the buffer status are described.
[0322] With respect to the Logical channel when the transmission
window of the RLC layer is Full and in stall mode, it is assumed
that there are no transmittable data.
[0323] When it is decided that an instruction for the handover
between the base station apparatuses is to be sent to the user
equipment (UE) terminal, with respect to a DTCH (Dedicated Traffic
CHannel) in the logical channel of the user equipment (UE)
terminal, it is assumed that there are no transmittable data.
Namely in this case, only the Downlink Control Channel (DCCH) in
the logical channel of the user equipment (UE) terminal is assumed
to be transmittable data. Further, with respect to MAC control
block, only when there is a MAC control block transmittable upon
the transmission of the Downlink Control Channel (DCCH), the
transmission is performed. Further, with respect to the MAC control
block, it may be assumed that there are transmittable data
regardless of the existence of the Downlink Control Channel (DCCH).
Otherwise, it may be assumed that there are no transmittable data
regardless of the existence of the Downlink Control Channel
(DCCH).
[0324] When the user equipment (UE) terminal hands over from
another base station (the source base station) apparatus to the
base station apparatus, it is assumed that there are no data
transmittable to the user equipment (UE) terminal until it is
determined that data can be transmitted to the user equipment (UE)
terminal. In this case, the base station apparatus 200 may
determine that data can be transmitted to the user equipment (UE)
terminal when, for example, the data transmission from the other
base station (the source base station) apparatus to the base
station apparatus is completed and a Status Report of the PDCP
layer is received. Further, the completion of the data transmission
from the other base station (the source base station) apparatus to
the base station apparatus may be defined by when, for example, a
timer is up by setting the timer to count time required (estimated)
to complete the data transmission. Further, it is assumed that the
determination of whether the Status Report of the PDCP layer is
received is performed with respect to only the logical channel
designated for the transmission of the Status Report of the PDCP
layer.
[0325] When the uplink synchronization status of the user equipment
(UE) terminal shows the synchronization loss, or when status of an
uplink dedicated resource is NG, it is assumed that there are no
transmittable data with respect to the DTCH of the user equipment
(UE) terminal and that only DCCH or MAC control block is regarded
as the transmittable data.
[0326] When the Persistent Resource is reserved in the sub-frame
(i.e., the process of step S1016 is performed), it is assumed that
there are no transmittable data with respect to the logical channel
(the logical channel to which the Persistent Scheduling is
applied). However, even in this case, in the process of
multiplexing the data in the RLC buffer of the MAC control block
and each Logical Channel with the MAC PDU in step S912, it is
assumed that there are transmittable data.
[0327] When only there is a MAC control block as the transmittable
data, the transmittable data are treated as the logical channel
belonging to the same Priority class as the DCCH belongs. Namely,
when only there is a MAC control block as the transmittable data,
it is assumed that there is a signal corresponding to transmittable
DCCH.
[0328] When the Persistent Resource is not reserved in the
sub-frame (i.e., the process of step S1016 is not performed), the
following process is performed with respect to the Logical Channel
to which the Persistent Scheduling is applied.
[0329] When the Data size of the new transmittable data is equal to
or greater than the threshold value
Threshold.sub.data.sub.--.sub.size, or when there are
retransmittable data, it is assumed that there are transmittable
data.
[0330] On the other hand, when the Data size of the new
transmittable data is less than the threshold value
Threshold.sub.data.sub.--.sub.size, it is assumed that there are no
transmittable data.
[0331] By performing this process, it may become possible to avoid
that, in the sub-frame to which the Persistent Resource is not
allocated, the transmission resource is allocated to the data to
which Persistent Scheduling is to be applied. Further, unless
otherwise described, a result of the determination "whether there
is transmittable data related to each logical channel" is also
applied of the process of multiplexing the data in the RLC buffer
of the MAC control block and each Logical Channel with the MAC PDU
in step S912. Namely when determining that "there are no
transmittable data", it is assumed that there are no transmittable
data as well in the process of multiplexing the data in the RLC
buffer of the MAC control block and each Logical Channel with the
MAC PDU in step S912.
[0332] When a result of the Buffer Status Check process is NG (NG
in step S1022), the user equipment (UE) terminal is excluded from a
target of the scheduling process. On the other hand, when the
result of the Buffer Status Check process is OK (OK in step S1022),
the logical channel having the Highest priority is selected from
among the logical channel having the transmittable data based on
the following Selection logics, and the process goes to step S1024
in which the Scheduling Coefficient Calculation process is
performed.
[0333] Selection logic 1: The logical channel having the highest
priority is defined as the logical channel having the Highest
priority.
[0334] Selection logic 2: When there are plural logical channels
satisfying the Selection logic 1, the logical channel(s) having the
transmittable data is defined as the logical channel(s) having the
Highest priority.
[0335] Selection logic 3: In a case where there are plural logical
channels satisfying the Selection logic 2, when there is a
Dedicated Control Channel (DCCH), the Dedicated Control Channel
(DCCH) is defined as the logical channel having the Highest
priority; and when there is no Dedicated Control Channel (DCCH),
any of the logical channels from among the plural logical channel
is determined as the logical channel having the Highest
priority.
[0336] When those selection logics are applied, not the
retransmission data of the logical channel having a lower priority
but the new data of the logical channel having a higher priority
are more likely to be determined as the data of the logical channel
having higher priority.
[0337] The above-described process that the user equipment is
excluded from a target of the scheduling process in steps S1006,
S1008, and S1002 means that the Scheduling Coefficient Calculation
process described below is not to be performed. As a result, in the
sub-frame, a Downlink Shared Channel (DSCH) is not transmitted to
the user equipment (UE). In other words, the base station apparatus
200 performs the scheduling with respect to the user equipment (UE)
terminals other than the user equipment (UE) terminals determined
to be excluded from the targets of the scheduling in the above
steps S1006, S1008, or S1002; namely the base station apparatus 200
selects user equipment (UE) terminals to which the shared channel
is to be transmitted and transmits downlink shared channel (DL-SCH)
to the selected user equipment (UE) terminals.
[0338] In step S1024, with respect to the logical channel
determined as the logical channel having the Highest priority in
step S1022, the Scheduling coefficients are calculated based on an
evaluation formula described below. Namely when there are plural
logical channels with respect to a certain user equipment (UE)
terminal, the Scheduling Coefficient Calculation is not performed
on all the logical channels but is performed only on the logical
channel having the highest priority. By doing this, it may become
possible to reduce the processing load of the base station
apparatus 200.
[0339] Tables 5 through 9 show parameters set via the external
input interface (I/F).
TABLE-US-00007 TABLE 5 Set with respect No Parameter name to each
Remarks 1 A.sub.pc Priority This is a Priority Class Priority level
class coefficient. Priority Class refers to an index or class
indicating a priority level of data defined with respect to each
logical channel. 2 D(flag.sub.DRX) UE A DRX priority level
coefficient given to preferentially transmit data of UE in DRX mode
and DRX reception timing. In the sub-frame, this value is set based
on a value of flag "flag.sub.DRX" related to the UE. When
flag.sub.DRX = 0, D(0) is set to a fixed value 1.0 (D(0) = 1.0),
and only when flag.sub.DRX = 1, this value is set via external
input interface (I/F). For example, when flag.sub.DRX = 1 , by
setting D(flag.sub.DRX) to 2.0 (D(flag.sub.DRX) = 2.0), it becomes
possible to preferentially transmit data of UE in DRX mode and DRX
reception timing. It is assumed that in DRX mode and DRX reception
timing, flag.sub.DRX is set to 1(flag.sub.DRX = 1), otherwise,
flag.sub.DRX is set to 0 (flag.sub.DRX = 0). 3
E.sub.PC(Num.sub.retex) Priority This is a retransmission priority
coefficient class used to preferentially transmit data to UE having
a large number of retransmission of HARQ. When there are plurality
of Processes having retransmission data, a value of the largest
number of the retransmission is defined as Num.sub.retx. Depending
on the value of the number of retransmission times, the setting
value of E.sub.PC(Num.sub.retex) is set as described above via the
external input interface (I/F). For example, as shown in the table
below By increasing the value of E.sub.PC(Num.sub.retex) as the
value of Num.sub.retx. increases, it becomes possible to
preferentially transmit data to UE having a large number of
retransmission of HARQ. Numretx setting value of EPC(Numretex) 0
1.0 1 1.2 2, 3 1.8 4-16 2.5
TABLE-US-00008 TABLE 6 Set with respect No Parameter name to each
Remarks 4 F.sub.PC(t.sub.RLC_buffered) Priority This is a residence
time priority level coefficient class used to preferentially
transmit data to UE in which buffer residence time of RLC is long.
The buffer residence time of RLC SDU related to a logical channel
having the Highest priority is used as an argument. The definition
of buffer residence time of RLC SDU is defined as an elapsed time
(unit: ms) from when "RLC SDU" is stored in Queue buffer provided
with respect to each logical channel. Herein the timing of "when
RLC SDU is stored in Queue buffer" is the same between for the
retransmission and for the initial transmission. If there are RLC
SDU having different Buffer residence time, the RLC SDU having the
longest Buffer residence time is defined as flag.sub.DRX. This
value is set based on the the buffer residence time
"t.sub.RLC_buffered" of RLC SDU as follows: [t.sub.RLC_buffered
< Th.sub.PC.sup.(RLC_buffered,1)] F.sub.PC(t.sub.RLC_buffered) =
0.0 [Th.sub.PC.sup.(RLC_buffered,1) .ltoreq. t.sub.RLC_buffered
< Th.sub.PC.sup.(RLC_buffered,2)] F PC ( t RLC _ buffered ) = t
RLC - buffered - Th LCP ( RLC _ buffered , 1 ) Th LCP ( RLC _
buffered , 2 ) - Th LCP ( RLC _ buffered , 1 ) ##EQU00008## However
when Th.sub.LCP.sup.(RLC-buffered,1) =
Th.sub.LCP.sup.(RLC-buffered,2) is satisfied, this process is
ineffective. [Th.sub.PC.sup.(RLC_buffered,2) .ltoreq.
t.sub.RLC_buffered] F.sub.PC(t.sub.RLC_buffered .gtoreq.
Th.sub.PC.sup.(RLC_buffered)) = 1.0 ##STR00001## As described
above, by increasing the value F.sub.PC(t.sub.RLC_buffered) when
the buffer residence time "t.sub.RLC_buffered" of RLC SDU exceeds a
predetermined value Th.sub.PC.sup.(RLC_buffered), it becomes
possible to preferentially transfer data to UE having longer Buffer
residence time of RLC.
TABLE-US-00009 TABLE 7 Set with respect No Parameter name to each
Remarks 5 Th.sub.pc.sup.(RLC.sup.--.sup.buffered, 1) Priority This
is a threshold value related to the Buffer class residence time of
the RLC SDU. 6 Th.sub.pc.sup.(RLC.sup.--.sup.buffered, 2) Priority
This is a threshold value related to the Buffer class residence
time of the RLC SDU. 7 G(flag.sub.control) UE This is a MAC control
block priority level coefficient used to preferentially transfer
data to UE having MAC control block to be transmitted. In the
sub-frame, this value is set based on a value of flag.sub.control
of UE. When flag.sub.control = 0, G(0) is set to a fixed value 1.0
(G(0) = 1.0), and only when flag.sub.control = 1, this value is set
via external input interface (I/F). For example, when
flag.sub.control = 1, by setting G(flag.sub.control) to 2.0
(G(flag.sub.control) = 2.0), it becomes possible to preferentially
transmit remaining data of UE having the MAC control block to be
transmitted. It is assumed that when there is MAC control block to
be transmitted, flag.sub.control is set to 1(flag.sub.control = 1),
otherwise, flag.sub.control is set to 0 flag.sub.control = 0).. 8
R.sub.pc.sup.(target) Priority This is a target data rate
(bits/sub-frame) class 9 .alpha..sup.(CQI) UE This is a weighting
coefficient with respect to priority level based on CQI. By using
this parameter, it becomes possible to put weighting on priority
levels based on CQI.
TABLE-US-00010 TABLE 8 Set with respect No Parameter name to each
Remarks 10 .alpha..sub.pc.sup.(retx) Priority This is a weighting
coefficient with respect to class priority level based on the
number of HARQ retransmissions. By using this parameter, it becomes
possible to put weighting on priority levels based on the number of
HARQ retransmissions. 11
.alpha..sub.pc.sup.(RLC.sup.--.sup.bufferred) Priority This is a
weighting coefficient with respect to class priority levels based
on Buffer residence amount of RLC. By using this parameter, it
becomes possible to put weighting on priority levels based on the
Buffer residence amount of RLC. 12 .alpha..sub.pc.sup.(rate)
Priority This is a weighting coefficient with respect to class
priority levels based on Average Data Rate. By using this
parameter, it becomes possible to put weighting on priority levels
based on the Average Data Rate. 13 .delta.'.sub.pc Priority A
convergence value of user data speed averaging class forgetting
coefficient for R.sub.n, k 14 Scheduling Priority An index of
Scheduling priority group set with priority group class respect to
each Priority class. Prioritization of index each UE is performed
in the order of "Scheduling priority group: High .fwdarw. Middle
.fwdarw. Low". Further, in each of the Scheduling priority groups,
prioritization is performed based on scheduling coefficients. The
priority order of the scheduling priority group is defined as
follows: High > Middle > Low.
[0340] Table 9 shows input parameters given to each logical channel
of each user equipment (UE) terminal by treating the sub-frame as a
unit.
TABLE-US-00011 TABLE 9 No. Parameter name Remarks 1 PC.sub.n, k
This parameter indicates Priority Class of the logical Channel #k
of UE#n. Priority class refers to an index or class indicating a
priority level of data defined with respect to each logical
channel. 2 R.sub.n This parameter indicates Instantaneous
transmittable Data Rate (bits/sub-frame) of UE#n calculated based
on the following formula: Rn = DL_Table_TF_SIZE(RB_all, L
CQIreceived .right brkt-bot.) Where RB_all: the number of RBs
across the system bandwidth Further, "CQIreceived" is calculated as
follows: (when DL transmission type = Distributed) CQIreceived =
CQI related to across the system bandwidth (when DL transmission
type = Localized) CQIreceived = CQI of RBgroup having the highest
quality The definition of the RBgroup corresponds to the definition
of the RB groups of CQI reported from UE. 3 R.sub.n, k This
parameter indicates the Average Data Rate (bits/sub-frame) of
logical channel #k of UE#n. R.sub.n, k(TTI) = .delta..sub.n, k
R.sub.n, k (TTI - 1) + (1 - .delta..sub.n, k)*r.sub.n, k r.sub.n,
k: instantaneous data rate As the initial value of R.sub.n, k,
R.sub.n, k calculated in the sub-frame is used .delta..sub.n, k:
forgetting coefficient which is a variable changing with respect to
each claculation period Calculation of R.sub.n, k is performed at
every sub- frame based on update timing with respect to not only a
logical channel having the Highest Priority but also any other
logical channels.
[0341] Based on the input parameters in Tables 5-8, the Scheduling
coefficient C.sub.n of the logical channel #h having the Highest
priority of the user equipment (UE) terminal #n is calculated based
on formula (1) below.
C.sub.n=A.sub.LPC.sub.h.times.D(flag.sub.DRX).times..alpha..sup.(CQI)R.s-
ub.n.times.(1+.alpha..sub.LPC.sub.h.sup.(retx)E.sub.LPC.sub.h(retx)+.alpha-
..sub.LPC.sub.h.sup.(RLC.sup.--.sup.buffered)F.sub.LPC.sub.h(t.sub.RLC.sub-
.--.sub.buffered)).times.G(flag.sub.control).times.exp(.alpha..sub.LPC.sub-
.h.sup.(rate)(R.sub.n,h.sup.(target)- R.sub.n,h)) (13)
[0342] Further, in a case of Intra-eNB Hand Over (Intra-eNB HO), it
is assumed that the measured value and calculated value used for
the Scheduling are not taken over into the Target eNB (eNB of
handover destination).
[0343] In step S1024, the Average Data Rate is measured.
[0344] The Average Data Rate is obtained by using the formula (2)
described above.
[0345] Where, N.sub.n,k(1, 2, . . . ) denotes the number of
updating the Average Data Rate. However, in the sub-frame where
N.sub.n,k=0, the formula (3) described above is applied.
[0346] Further, a forgetting coefficient .delta..sub.n,k is
calculated as follows.
.delta..sub.n,k=min(1-1/N.sub.n,k,.delta.'.sub.PCn,k)
[0347] An updating timing of the Average Data Rate is based on
"every sub-frame where there are data to be transmitted to the data
buffer of the logical channel #k of the base station apparatus
200". Further, r.sub.n,k is calculated as a transmitted "size of
transmitted MAC SDU". Namely the calculation of the Average Data
Rate is performed based on any of the following operations in the
sub-frame when the Average Data Rate is to be updated.
[0348] 1. For a user equipment (UE) terminal that transmits data,
the Average Data Rate is calculated assuming "r.sub.n,k=size of
transmitted MAC SDU".
[0349] 2. For a user equipment (UE) terminal that has not
transmitted data, the Average Data Rate is calculated assuming
"r.sub.n,k=0".
[0350] In this case, the Average Data Rate is calculated when
determining that at least one CQI is received in the past in the
Received CQI Check process and conditions of updating the Average
Data Rate are matched. Namely the calculation is started after the
CQI is received at least once.
[0351] Next, in step S1026, N.sub.Scheduling indicating the number
of user equipment (UE) terminals that calculate the Scheduling
coefficient is increased by 1 (one). In step S1028, a value of "n"
indicating the index of the user equipment (UE) terminal is
increased by 1 (one).
[0352] Next, in step S1030, it is determined whether n is equal to
or less than N. When determining that n is equal to or less than N
(YES in step S1030), the process goes back to step S1004.
[0353] On the other hand, when determining that n is greater than N
(NO in step S1030), the process goes to step S1032 in which a UE
Selection process is performed. More specifically, in step S1032,
the user equipment (UE) terminal is selected in which the
allocation of the radio resources is performed based on the Dynamic
scheduling with respect to the sub-frame.
[0354] First, by the following formula, the number "N.sub.DL-SCH"
of user equipment (UE) terminals in which the radio resources are
allocated based on the Dynamic scheduling (i.e., the number of user
equipment (UE) terminals transmitting the Downlink Shared Channel
(DL-SCH)) is calculated. Herein, a symbol N.sub.Scheduling denotes
the number of user equipment (UE) terminals in which the Scheduling
Coefficient Calculation process has been performed (see FIG.
10).
N.sub.DL-SCH=min(N.sub.Scheduling,N.sub.DLMAX-N.sub.PCH-N.sub.RACHres-N.-
sub.D-BCH-N.sub.RACHm4-N.sub.MCH)
[0355] When the number "N.sub.DL-SCH" of user equipment (UE)
terminals transmitting the Downlink Shared Channel (DL-SCH)) is
calculated, if inequality N.sub.DL-SCH<0 is satisfied, the
transmission process of the sub-frame is sequentially prohibited in
the order of RACH message4, RACH response, MCH, PCH, and D-BCH.
When determined that the transmission of the sub-frame is
prohibited in a channel, the channel is not transmitted using the
sub-frame.
[0356] Next, top N.sub.DL-SCH user equipment (UE) terminals in
which the resource blocks are allocated based on the Dynamic
scheduling are selected, the top N.sub.DL-SCH user equipment (UE)
terminals having larger Scheduling coefficients calculated in step
S1024 with respect to each Scheduling priority group of the logical
channel having the Highest priority. Namely user equipment (UE)
terminals that become the transmission destinations of the downlink
Shared Channel (DL-SCH) are selected. Herein, the Scheduling
priority group refers to a group prioritized in the Scheduling
process and a Scheduling priority group to which the logical
channel is to belong is defined with respect to each logical
channel. Namely each user equipment (UE) terminal is classified
(hierarchized) into the Scheduling priority groups based on the
logical channel having the Highest priority; and in each of the
Scheduling priority groups, user equipment (UE) terminals to become
the destinations of the downlink shared channel (DL-SCH) to which
the Dynamic scheduling is applied are sequentially selected in the
descending order of the Scheduling Coefficients calculated in step
S1024 (i.e., the scheduling (process) is performed).
[0357] The above "user equipment (UE) terminals" are selected in
accordance with the following order. [0358]
High(1.sup.st).fwdarw.High(2.sup.nd).fwdarw. . . . .fwdarw.Middle
(1.sup.st).fwdarw.Middle(2.sup.nd).fwdarw. . . .
.fwdarw.Low(1.sup.st).fwdarw.Low(2.sup.nd).fwdarw. . . . .
[0359] When the user equipment (UE) terminal has control
information of the MAC layer to be transmitted in the sub-frame,
the Scheduling priority group is set to "High" regardless of the
Scheduling priority group of the logical channel having the Highest
priority. Namely, the base station apparatus 200 performs the
Scheduling assuming that, in the sub-frame, the user equipment (UE)
terminal having the control information of the MAC layer to be
transmitted belongs to the Scheduling priority group having higher
priority level.
[0360] Further, in the above example, the Scheduling priority group
has three types, High, Middle, and Low. However, for example, Super
High may be added and defined. In this case, for example, a
priority level flag which is set only when a congestion degree of
the cell is high is defined, and the user equipment (UE) terminal
or the logical channel in which the priority level flag is ON may
be assumed to belong to the Super High Scheduling priority group.
The user equipment (UE) terminal or the logical channel in which
the priority level flag is set may transmit/receive an emergency
call or a priority call. Further, when the congestion degree of the
cell is high, the base station apparatus 200 may reserve resources
in the base station apparatus 200 for the user equipment (UE)
terminal or the logical channel in which the priority level flag is
set. Further, the resources may include CPU capacity, memory
capacity, baseband resource, transmission power resource, frequency
resource, resource in time direction and the like. Further, to
reserve the resources, the number of the user equipment (UE)
terminals may be limited; namely the maximum number of user
equipment (UE) terminals to be connected in the cell may be
reduced.
[0361] Further, with respect to the user equipment (UE) terminal in
which the priority level flag is set or the user equipment (UE)
terminal having a logical channel in which the priority level flag
is set, all the logical channel provided in the user equipment (UE)
terminal may belong to the Super High Scheduling priority group. In
this case, to any of the logical channels provided in the user
equipment (UE) terminal, resources are preferentially allocated,
i.e., shared channels are allocated.
[0362] The priority level flag may be reported from the core
network.
[0363] As described above, it may become possible to calculate the
Scheduling coefficients with respect to each user equipment (UE)
terminal that is determined to be able to transmit the downlink
shared channel (DL-SCH) by performing the loop process with respect
to "n" which is the index of the user equipment (UE index).
Further, the radio resources are allocated to the user equipment
(UE) terminals having a greater calculated Scheduling coefficient
value. Namely it may become possible to determine the user
equipment (UE) terminals to which the radio resources (downlink
shared channel (DL-SCH)) are allocated and transmit the downlink
shared channel (DL-SCH) to the user equipment (UE) terminals based
on the priority level of data, radio quality information reported
from the user equipment (UE) terminal, the number of
retransmission, whether there is control information of the MAC
layer, frequency of allocation, the average data rate, and the
target data rate, whether the handover process is being performed,
whether it is in the reception timing of the intermittent reception
process, whether it is in a residence time of data in the RLC
(Radio Link Control) layer, and whether it is in the reception
timing in the mode of measuring a cell operated at a different
frequency by performing control of transmitting the downlink shared
channel (DL-SCH), in which DL-SCH is transmitted to the user
equipment (UE) terminals having larger scheduling coefficients. In
the above example, the Scheduling priority group has three types,
High, Middle, and Low. However, four or more types of the
Scheduling priority group may be provided, or two or less types of
the Scheduling priority group may be provided.
[0364] For example, five types, i.e., High.sub.MAC, High.sub.DRX,
High, Middle, and Low, of the Scheduling priority groups may be
provided assuming that the priority level decreases in the order of
High.sub.MAC, High.sub.DRX, High, Middle, and Low. Further, in this
case, with respect to the user equipment (UE) terminals having an
MAC control block to be transmitted, the Scheduling priority may be
set to "High.sub.MAC" regardless of the Scheduling priority group
of the logical channel having the Highest priority. Further, with
respect to the user equipment (UE) terminal in a DRX reception
timing in DRX mode, the Scheduling priority group may be set
"High.sub.DRX" regardless of the Scheduling priority group of the
logical channel having the Highest priority. By doing this, it may
become possible to preferentially allocate the shared channel with
respect to the user equipment (UE) terminal having the MAC control
block to be transmitted and the user equipment (GE) terminal in the
DRX reception timing in DRX mode. For example, when there are user
equipment (UE) terminal(s) having the MAC control block and user
equipment (UE) terminal(s) without the MAC control block, it may
become possible to preferentially allocate the shared channel to
the user equipment (UE) terminal(s) having the MAC control block
regardless of the value of C.sub.n in formula (1).
[0365] In the above example, the priority level is set so that the
priority level decreases in the order of High.sub.MAC,
High.sub.DRX, High, Middle, and Low. However, this is just an
example only, and, for example, the priority level may be set so
that the priority level decreases in the order of High,
High.sub.MAC, High.sub.DRX, Middle, and Low.
[0366] Next, the downlink TFR Selection (DL TFR Selection) process
performed in step S912 is described with reference to FIG. 11.
[0367] FIG. 11 shows a procedure of the DL TFR selection process.
By performing this procedure, it may become possible to determine
the transmission formats of and allocate the radio resources to the
Synchronization Signal (also called a Synchronization channel
(SCH)), the Primary Broadcast Channel (P-BCH), the Paging Channel
(PCH), the Dynamic Broadcast Channel (D-BCH), the Random Access
Channel (RACH) response (RACH response, or message2 in random
access procedure), the Message4 in random access procedure, the
MBMS channel (MCH), the Downlink Shared Channel (DL-SCH) to which
the Persistent Scheduling is applied, and the Downlink Shared
Channel (DL-SCH) to which the Dynamic Scheduling is applied. The
above SCH, P-BCH, PCH, D-BCH, RACH response, RACH Message4 are
called common channels.
[0368] First, in step S1102, Resource Blocks are allocated to the
Common Channels (RB allocation for Common channel is
performed).
[0369] When the Synchronization signal is transmitted using the
sub-frame, six or seven resource blocks in the substantially center
portion of the system bandwidth are allocated to the
Synchronization signal. The RB group including the RB allocated to
the Synchronization signal is not allocated to the downlink shared
channel (DL-SCH) to which the Dynamic Scheduling is applied.
[0370] The above-mentioned resource blocks allocated to the
Synchronization signal are treated as the resource blocks reserved
for the Synchronization signal to prevent the resource blocks from
being allocated to any other channel. However, not all the resource
blocks having been reserved for the Synchronization signal are
practically allocated to the Synchronization signal. Namely the
Synchronization signal is allocated to only predetermined
sub-carriers among all the resource blocks having been allocated
for the Synchronization signal.
[0371] The transmission power of the Synchronization signal (total
of transmission power of all the resource elements (sub-carriers);
absolute value; unit is W) is defined as P.sub.SCH.
[0372] When the Primary Broadcast Channel (P-BCH) is transmitted
via the sub-frame, six or seven resource blocks in the
substantially center portion of the system bandwidth are allocated
to the Primary Broadcast Channel (P-BCH). The above-mentioned
resource blocks allocated to the Primary Broadcast Channel (P-BCH)
are treated as the resource blocks reserved for the Primary
Broadcast Channel (P-BCH) to prevent the resource blocks from being
allocated to any other channel. However, not all the resource
blocks having been reserved for Primary Broadcast Channel (P-BCH)
are practically allocated to the Primary Broadcast Channel (P-BCH).
Namely the Primary Broadcast Channel (P-BCH) is allocated to only
predetermined sub-carriers among all the resource blocks having
been allocated for the Primary Broadcast Channel (P-BCH). For
example, the Primary Broadcast Channel (P-BCH) may be mapped to the
sub-carriers having the same sub-carrier numbers as the
Synchronization signal is mapped.
[0373] The transmission power of the Primary Broadcast Channel
(P-BCH) (total of transmission power of all the resource elements
(sub-carriers); absolute value; unit is W) is defined as
P.sub.P-BCH.
[0374] When the Paging Channel (PCH) is transmitted via the
sub-frame, the RB group determined in advance is allocated to the
Paging Channel (PCH). Otherwise, in accordance with the data size
of the Paging Channel (PCH) or the number of user equipment (UE)
terminals transmitting the Paging Channel (PCH), or in accordance
with available RB group, the RB group may be allocated to the
Paging Channel (PCH). For example, within available RB groups, RB
groups may be sequentially selected from both ends of the system
bandwidth until the necessary number of the resource blocks of the
selected RB groups have been selected, the necessary number of the
resource blocks being determined based on the data size of the
Paging Channel (PCH); and the selected RB groups are allocated to
the Paging Channel (PCH). Herein, the available RB group refers to
the RB group which has not been determined to be allocated to any
of the other channels at the timing when this process is
performed.
[0375] When the Random Access Channel response (RACH response or
Message2 in random access procedure) is transmitted via the
sub-frame, the RB group determined in advance is allocated to the
RACH response. Otherwise, in accordance with the data size of the
RACH response or the number of user equipment (UE) terminals
transmitting the RACH response, or in accordance with available RB
group, the RB group may be allocated to the RACH response. For
example, within available RB groups, RB groups may be sequentially
selected from both ends of the system bandwidth until the necessary
number of the resource blocks of the selected RB groups have been
selected, the necessary number of the resource blocks being
determined based on the data size of the RACE response; and the
selected RB groups are allocated to the RACH response. Herein, the
available RB group refers to the RB group which has not been
determined to be allocated to any of the other channels at the
timing when this process is performed.
[0376] When the Dynamic Broadcast Channel (D-BCH) is transmitted
via the sub-frame, the RB group determined in advance is allocated
to the Dynamic Broadcast Channel (D-BCH). Otherwise, in accordance
with the data size of the Dynamic Broadcast Channel (D-BCH) or the
number of user equipment (UE) terminals transmitting the Dynamic
Broadcast Channel (D-BCH), or in accordance with available RB
group, the RB group may be allocated to the Dynamic Broadcast
Channel (D-BCH). For example, within available RB groups, RB groups
may be sequentially selected from both ends of the system bandwidth
until the necessary number of the resource blocks of the selected
RB groups have been selected, the necessary number of the resource
blocks being determined based on the data size of the Dynamic
Broadcast Channel (D-BCH); and the selected RB groups are allocated
to the Dynamic Broadcast Channel (D-BCH). Herein, the available RB
group refers to the RB group which has not been determined to be
allocated to any of the other channels at the timing when this
process is performed.
[0377] When the RACH message4 is transmitted via the sub-frame, the
RB group determined in advance is allocated to the RACH message4.
Otherwise, in accordance with the data size of the RACH message4 or
the number of user equipment (UE) terminals transmitting the RACH
message4, or in accordance with available RB group, the RB group
may be allocated to the RACH message4. For example, within
available RB groups, RB groups may be sequentially selected from
both ends of the system bandwidth until the necessary number of the
resource blocks of the selected RB groups have been selected, the
necessary number of the resource blocks being determined based on
the data size of the RACH message4; and the selected RB groups are
allocated to the RACH message4. Herein, the available RB group
refers to the RB group which has not been determined to be
allocated to any of the other channels at the timing when this
process is performed.
[0378] In step S1104, the allocation of resource blocks to the MBMS
channel (i.e., MCH) (RB allocation (process) for MCH) is performed.
Namely when the MCH is transmitted via the sub-frame, the RB group
determined in advance is allocated to the MCH. Otherwise, in
accordance with the data size of the MCH or the number of user
equipment (UE) terminals transmitting the MCH, or in accordance
with available RB group, the RB group may be allocated to the MCH.
For example, within available RB groups, RB groups may be
sequentially selected from both ends of the system bandwidth until
the necessary number of the resource blocks of the selected RB
groups have been selected, the necessary number of the resource
blocks being determined based on the data size of the MCH; and the
selected RB groups are allocated to the MCH. Herein, the available
RB group refers to the RB group which has not been determined to be
allocated to any of the other channels at the timing when this
process is performed.
[0379] Next, in step S1106, the allocation of resource blocks for
Persistent Scheduling (RB allocation (process) for Persistent
Scheduling) is performed. In step S1106, the Persistent Resources
reserved in step S1106 are allocated to the user equipment (UE)
terminal having the downlink shared channel (DL-SCH) to which the
Persistent scheduling is applied in the sub-frame.
[0380] However, with respect to the user equipment (UE) terminal to
which the Persistent scheduling is applied in the sub-frame, the
Scheduling coefficient described in steps S1024 is calculated. When
the transmission resource are allocated for the Logical channel to
which the Dynamic scheduling is applied in the sub-frame, the base
station apparatus 200 releases the Persistent Resources and
transmits the MAC PDU (DL-SCH) to the user equipment (UE) terminal
using Resources allocated for the Logical Channel to which the
Dynamic scheduling is applied. The method of multiplexing the data
in the RLC buffer of the MAC control block and each Logical channel
with the MAC PDU is described below.
[0381] The transmission power of the downlink shared channel
(DL-SCH) to which the Persistent scheduling is applied (total of
transmission power of all the resource elements (sub-carriers);
absolute value; unit is W) is defined as P.sub.persist. Herein,
when there are two or more user equipment (UE) terminals having the
downlink shared channel (DL-SCH) to which the Persistent scheduling
is applied, P.sub.persist represents the total amount of the
transmission power of the downlink shared channel (DL-SCH) of all
the user equipment (UE) terminals, the Persistent scheduling being
applied to the downlink shared channel (DL-SCH).
[0382] Next, in step S1108, a Calculation for Number of RBs for
PDSCH (i.e., a calculation of the number of the resource blocks of
the Physical Downlink Shared Channel (PDSCH)) is performed. More
specifically, the number of the resource blocks
"N.sub.dynamic.sup.(RB)" that can be allocated to the Physical
Downlink Shared Channel (PDSCH) using the following formula (14)
based on the maximum transmission power of the base station
apparatus 200 (hereinafter referred to as "P.sub.max": unit:W)
transmission power of Synchronization signal "P.sub.SCH",
transmission power of Primary Broadcast Channel
(P-BCH)"P.sub.P-BCH", transmission power of Paging Channel (PCH)
"P.sub.PCH", transmission power of Random Access Channel (RACH)
response "P.sub.RACHres" transmission power of Dynamic Broadcast
Channel (D-BCH) "P.sub.D-BCH", transmission power of RACH message4
"P.sub.RACHm4", transmission power of MBMS channel
(MCH)"P.sub.MCH", transmission power per one resource block of
downlink shared channel (DL-SCH) to which Persistent scheduling is
applied "P.sub.persist", and transmission power per one resource
block of downlink shared channel (DL-SCH) to which Dynamic
scheduling is applied "P.sub.dynamic". Herein, a symbol
"N.sub.dynamic.sup.(RB)" denotes the number of resource blocks of
the entire system bandwidth, and symbols "N.sub.P-BCH" "N.sub.SCH",
"N.sub.PCH", "N.sub.RACHres", "N.sub.D-BCH", "N.sub.RACHm4",
"N.sub.MCH", and "N.sub.persist" denote the numbers of resource
blocks allocated to the P-BCH, Synchronization signal, PCH, RACH
response, D-BCH, RACH message4, MCH, and the downlink shared
channel (DL-SCH) to which the Persistent scheduling is applied,
respectively in the sub-frame.
N dynamic ( RB ) = min ( N system ( RB ) - N common - N persist P
ma x - max ( P SCH , P P - BCH ) - P D - BCH - P persist - P PCH -
P RACHres - P RACHres - P MCH P dynamic ( RB ) ) ( 14 )
##EQU00009##
[0383] When inequality
N.sub.dynamic.sup.(RB)<N.sub.system.sup.(RB)-N.sub.common-N.sub.persis-
t is satisfied, the total transmission power value of the base
station apparatus 200 is controlled so that the total transmission
power value is equal to or less than the maximum transmission power
value of the base station apparatus 200 by preventing the
transmission using some RB group(s) among the RB groups other than
the RB groups allocated to the P-BCH, PCH, RACH response, D-BCH,
MCH, RACH message4 and downlink shared channel (DL-SCH) to which
Persistent scheduling is applied. More specifically, until the
transmission of
"N.sub.system.sup.(RB)-N.sub.common-N.sub.persistent-N.sub.dynamic.sup.(R-
B)" or more resource blocks is prohibited, the following process is
performed to determine the RB group that is prevented from being
transmitted. In this process, first, a RB group having the smallest
number of resource blocks is detected and the transmission of the
detected RB group is prohibited. In this case, if there are two or
more RB groups having the smallest number of resource blocks, the
transmission of the RB groups is sequentially prohibited in the
ascending order of the RB group number. The above process is
repeated to sequentially determine the RB groups that are prevented
from being transmitted. In the above example, a process is
performed in which the transmission of the RB groups is
sequentially prohibited in the ascending order of the RB group
number. However, alternatively, the transmission of the RB groups
may be sequentially prohibited in the descending order of the RB
group number, the transmission of the RB groups may be sequentially
prohibited from the RB groups at the center of the system bandwidth
to the RB groups at the both edges of the system bandwidth, the
transmission of the RB groups may be prohibited in any method other
than the methods described above.
[0384] In step S1110, the value of "k" is set to 1 (one) (k=1).
[0385] Next, in step S1112, the RB Remaining Check process to
determine whether there are any remaining resource blocks is
performed.
[0386] More specifically, in step S1112, it is determined whether
there is any remaining RB group that can be allocated to the
downlink shared channel (DL-SCH) to which Dynamic scheduling is
applied. When determining that there is an allocatable RB group,
the OK is returned. On the other hand, when determining that there
is no allocatable RB group, the NG is returned. When a result of
the RB Remaining Check is NG (NG in step S1112), the DL TFR
Selection process is terminated.
[0387] The above-mentioned "RB group that can be allocated to the
downlink shared channel (DL-SCH) to which Dynamic scheduling is
applied" refers to an RB group other than the RB groups having been
allocated to any of P-BCH, PCH, RACH response, D-BCH, RACH
message4, MCH, DL-SCH to which Persistent scheduling is applied,
and DL-SCH to which Dynamic scheduling is applied and in which the
TFR Selection process is already performed. Further, the number of
resource blocks included in the "RB groups that can be applied to
the downlink shared channel (DL-SCH) to which Dynamic scheduling is
applied" is defined as N.sub.remain.sup.(RB).
[0388] In the above example, it is assumed that "RB group that can
be allocated to the downlink shared channel (DL-SCH) to which
Dynamic scheduling is applied" refers to an RB group other than the
RB groups having been allocated to any of P-BCH, PCH, RACH
response, D-BCH, PACH message4, MCH, DL-SCH to which Persistent
scheduling is applied, and DL-SCH to which Dynamic scheduling is
applied and in which the TFR Selection process is already
performed. However, alternatively, RB group that can be allocated
to the downlink shared channel (DL-SCH) to which Dynamic scheduling
is applied" may be an RB group other than the RB groups having been
allocated to any of Synchronization signal, P-BCH, PCH, RACH
response, D-BCH, PACH message4, MCH, DL-SCH to which Persistent
scheduling is applied, and DL-SCH to which Dynamic scheduling is
applied and in which the TER Selection process is already
performed.
[0389] On the other hand, when the result of the RB Remaining Check
is OK (OK in step S1112), the process goes to step S1114.
[0390] Next, in step S1114, the DL TFR Selection (Downlink TFR
Selection) process is performed.
[0391] More specifically, the transport format of "the user
equipment (UE) terminal in which radio resources are allocated
based on Dynamic scheduling" determined in step S1032 is determined
and the allocation of the RB groups is performed.
[0392] The loop of steps S1110 through S1120 (see FIG. 11) based on
a value of "k" is to be performed in accordance with the order of
the selected "user equipment (UE) terminals in which radio
resources are allocated based on Dynamic Scheduling" in step
S1032.
[0393] In the DL TER selection process, a CQI adjustment process is
performed. With respect to the CQI used in the TFR Selection
process, the following processes are applied; the frequency
direction regarding process, the Outer-loop type offset adjustment
process, and the offset process based on the priority level of the
logical channel having the Highest priority.
[0394] Next the frequency direction regarding process is
described.
[0395] Based on the CQI values reported from the user equipment
(BE) terminal, a CQI value of each RB group is calculated. In this
case, if the CQI value across the system bandwidth (Wideband CQI)
is reported but there is no CQI value of UE selected sub-band in a
user equipment (UE) terminal, it is assumed that the same value of
the Wideband CQI is used as the CQI value of UE selected sub-band
in the user equipment (UE) terminal. In step S1020, with respect to
the user equipment (UE) terminal in which the transmission type is
determined as Distributed (transmission), it may be assumed that
the CQI values of all the RB groups are the same as the Wideband
CQI (the CQI value across the system bandwidth).
[0396] In the following, when the CQI related to the entire system
bandwidth is expressed, an argument is described as "all".
[0397] Next, the Outer-loop type offset adjustment process (CQI
offset adjustment) is described.
[0398] CQI_offset.sub.i is adjusted like an Outer loop as shown in
formula (8) described above based on the acknowledgement
information (a result of CRC check) of the downlink shared channel
(DL-SCH) where the priority class of the logical channel having the
Highest priority is X.sub.j,adjust. When the priority class of the
logical channel having the Highest priority is other than
X.sub.j,adjust, the Outer-loop type offset adjustment process (in
formula (8)) is not performed.
[0399] With respect to the user equipment (UE) terminal, when two
or more MAC PDU are to be transmitted within one sub-frame, the
Outer-loop type offset adjustment process is performed on each of
the two or more MAC PDU. Herein, the transmission of two or more
MAC PDU corresponds to the transmission based on two or more
codewards when MIMO is applied.
[0400] The CQI_offset.sub.i is adjusted with respect to each user
equipment (UE) terminal. Further, Priority class X.sub.j,adjust as
the target of the CQI offset adjustment process is set via the
external input interface (I/F). As described above, by performing
the Outer-loop type offset adjustment process with respect to one
priority class having been determined in advance instead of
performing the Outer-loop type offset adjustment process with
respect to all the priority classes, it may become possible to
reduce the processing load of the base station apparatus. For
example, as the Priority class X.sub.j,adjust, the Priority class
to which the logical channel having the greatest transmission
probability belongs is set.
[0401] .DELTA..sub.adj.sup.(PC) and BLER.sub.target.sup.(PC) may be
configured to be set via the external input interface (I/F).
However, it is assumed that the maximum value of CQI_offset.sub.i
is defined as CQI_offset.sub.PC.sup.(max), and the minimum value of
CQI_offset.sub.i is defined as CQI_offset.sub.PC.sup.(min). The
maximum value CQI_offset.sub.PC.sup.(max) and the minimum value
CQI_offset.sub.PC.sup.(min) of the CQI_offset.sub.i are set via the
external input interface (I/F). When the CQI_offset.sub.i is fixed
to the maximum value or the minimum value, the calculation of
formula (8) described above is not performed.
[0402] Then, the value of CQI_offset.sub.i is added to the value of
CQI of each RB group and a value of CQI related to the entire
system bandwidth as a power offset value. A process of the formula
(5) described above is performed with respect to each sub-frame in
which the DL TFR Selection process is performed regardless of
"whether the priority class of the logical channel having the
Highest priority is X.sub.j,adjust in the sub-frame".
[0403] Next, the offset process based on the priority level is
described.
[0404] The CQI values of the corresponding RB groups and the CQI
value related to the entire system bandwidth are adjusted using an
offset value .DELTA..sub.PC which is based on the priority level of
the logical channel having the Highest priority. The .DELTA..sub.PC
may be set via the external input interface (I/F). The subscriber
"pc" denotes Priority Class.
CQI.sub.adjust(i)=CQI.sub.adjust(i)-.DELTA..sub.pc
[0405] Next, a resource block group allocation (RB group
allocation) is described with reference to FIG. 12. By performing
the process below, the RB group is allocated to kth user equipment
(excluding PCH and RACH response) in which radio resources are
allocated based on the Dynamic Scheduling. FIG. 6 schematically
shows a DL_TF_Related_table and a case where CQI=1 as an
example.
Process
[0406] The following parameters are set in step S1202. [0407]
N.sub.remain.sup.(RB): the number of remaining resource blocks
(Number of Remaining RBs) [0408] N.sub.capability: the maximum RB
number [0409] N.sub.max,bit: the maximum data size (Payload size)
determined based on UE category
[0410] Herein, N.sub.capability may be set as a parameter in the
apparatus or as a parameter to be input from an upper node, or may
be set based on the information included in "GE capability"
reported from the user equipment (UE) terminal.
[0411] Further, in a case where an instruction to reduce the data
rate is issued from the user equipment (GE) terminal, the
N.sub.capability may be calculated based on the following
formula.
N.sub.capability=N.sub.capability*.alpha.
[0412] Herein, a symbol .alpha. may denote a ratio against the
maximum receivable throughput of the user equipment (UE) terminal.
For example, when the base station apparatus 200 receives an
instruction (request) from the user equipment (UE) terminal to
transmit the downlink shared channel (DL-SCH) at the rate of 80% or
less of the maximum receivable throughput of the user equipment
(UE) terminal, .alpha. may be set to 0.8 (.alpha.=0.8). Further, as
the method of reporting the instruction (request) by the user
equipment (UE) terminal, in a case where data rate is required to
be reduced, the ratio against the maximum receivable throughput of
the user equipment (UE) terminal or an absolute throughput value
may be reported. In any case, the base station apparatus 200 may
calculate the value of .alpha. by deriving the ratio against the
maximum receivable throughput of the user equipment (UE) terminal
from an instruction from the user equipment (UE) terminal to
perform the calculation of the above formula.
[0413] Further, in a case where an instruction to reduce the data
rate is issued from the user equipment (UE) terminal, the
N.sub.max,bit may be calculated based on the following formula.
N.sub.max,bit=N.sub.max,bit*.alpha.
[0414] Herein, a symbol .alpha. may denote a ratio against the
maximum receivable throughput of the user equipment (UE) terminal.
For example, when the base station apparatus 200 receives an
instruction (request) from the user equipment (UE) terminal to
transmit the downlink shared channel (DL-SCH) at the rate of 80% or
less of the maximum receivable throughput of the user equipment
(UE) terminal, .alpha. may be set to 0.8 (.alpha.=0.8). Further, as
the method of reporting the instruction (request) by the user
equipment (UE) terminal, in a case where data rate is required to
be reduced, the ratio against the maximum receivable throughput of
the user equipment (UE) terminal or an absolute throughput value
may be reported. In any case, the base station apparatus 200 may
calculate the value of .alpha. by deriving the ratio against the
maximum receivable throughput of the user equipment (UE) terminal
from an instruction from the user equipment (UE) terminal to
perform the calculation of the above formula.
[0415] Next, in step S1204, the number "N.sub.allocated.sup.(RB)"
of resource blocks allocatable to the user equipment (UE) terminal
is calculated.
N.sub.remain.sup.(UE)=min(N.sub.DL-SCH-k+1,N.sub.capability)
[0416] Based on this formula, it may become possible to control the
number of resource blocks allocated to the user equipment (UE)
terminal to be equal to or less than N.sub.capability. Herein,
min(A,B) refers to a function to output A or B whichever is
smaller.
N allocated ( RB ) = min ( N remain ( RB ) N remain ( UE ) , N
capability ) ( 15 ) ##EQU00010##
[0417] In step S1206, it is determined whether the downlink
transmission type is Localized or Distributed.
[0418] When determining that the downlink transmission type is
Distributed (result of determination in step S1206 is Distributed),
the process goes to step S1208. In step S1208, RB groups are
selected so that the allocated frequency resources can be
discretely distributed within the system bandwidth until the number
of the allocated resource blocks exceeds N.sub.allocated.sup.(RB)
or more. For example, the RB groups may be selected so that the
allocated frequency resources can be discretely distributed within
the system bandwidth by alternately assigning (selecting) the RB
blocks from both ends of the system bandwidth. Otherwise, the RB
groups may be selected so that the allocated frequency resources
can be discretely distributed within the system bandwidth by
alternately selecting from both the RB group having the largest RB
group number and the RB group having the smallest RB group
number.
[0419] When determining that the downlink transmission type is not
Distributed (i.e., Localized; result of determination in step S1206
is Localized), the process goes to step S1210. In step S1210, the
RB groups are sequentially allocated to the user equipment (UE)
terminal in the descending order of the values of CQI.sub.adjusted
until the number of resource blocks allocated to the user equipment
(UE) terminal reaches N.sub.allocated.sup.(RB) or more.
[0420] Before determining whether the downlink transmission type is
Localized or Distributed in step S1206, a method of allocating the
RB groups to the user equipment (UE) terminal may be determined
based on the path loss value between the user equipment (UE)
terminal and the base station apparatus 200. For example, after a
threshold value Threshold.sub.DL,PL is defined, when determining
that the path loss value is greater than the threshold value
Threshold.sub.DL,PL, the RB groups are sequentially allocated to
the user equipment (UE) terminal in the descending order of the
frequency values of the RB groups until the number of the resource
blocks allocated to the user equipment (UE) terminal reaches
N.sub.allocated.sup.(RB) or more. On the other hand, when
determining that the path loss value is equal to or less than the
threshold value Threshold.sub.DL,PL, the above determination
whether the downlink transmission type is Localized or Distributed
is performed, and the allocation of the RB groups may be performed
based on the result of the determination. Otherwise, in the above
process, when determining that the path loss values is equal to or
less than the threshold value Threshold.sub.DL,PL, without
determining whether the downlink transmission type is Localized or
Distributed, the RB groups may be sequentially allocated to the
user equipment (UE) terminal in the ascending order of the
frequency values of the RB groups. Further, the path loss value may
be calculated based on the UE Power Headroom and uplink shared
channel reported from the user equipment (UE) terminal and the
received quality of the Sounding reference signal or based on the
path loss value reported from the user equipment (GE) terminal. In
this case, the path loss value calculated from the UE Power
Headroom, uplink shared channel, or the received quality of the
Sounding reference signal reported from the user equipment (UE)
terminal corresponds to the uplink path loss value, and the path
loss value reported from the user equipment (UE) terminal
corresponds to the downlink path loss value.
[0421] For example, in an LTE system employing the FDD (Frequency
Division Duplex) scheme is employed, the uplink transmission signal
in the user equipment (UE) terminal may become an interference
signal to the downlink reception signal; and as a result, the
quality of the downlink reception signal may be degraded.
Generally, in user equipment (UE) terminals, there is a functional
section called a Duplexer, which prevents the leakage of the uplink
transmission signal into the functional section receiving a
downlink signal and performing the demodulation and decoding.
However, the leakage cannot be fully prevented. FIG. 14
schematically shows the mechanism of interference in the user
equipment (UE) terminal. As shown in FIG. 14, the transmission
signal generated in the transmission section is leaked into the
receiving section without the power of the transmission signal
being fully reduced in the Duplexer, and the leaked transmission
signal may become an interference signal which degrades the quality
of the received signal.
[0422] The more separated the difference is between the frequency
of the uplink transmission signal and the frequency of the downlink
reception signal, or the smaller the transmission power of the
uplink transmission signal is, the smaller the leakage becomes.
Further, in uplink, the larger the path loss value is, the larger
the transmission power becomes. Therefore, when the path loss value
is relatively large, by allocating the frequency resource having a
higher frequency, it may become possible to reduce the interference
of the uplink transmission signal to the downlink reception signal.
FIG. 15 schematically shows an effect caused by reducing the
interference of the uplink transmission signal to the downlink
reception signal. As shown in FIG. 15, when path loss value is
relatively large, a UL frequency band and a DL frequency band is
more separated from each other. Namely when the path loss value is
relatively large, a frequency band allocated to the DL transmission
signal to the user equipment (UE) terminal is more separated from
the UL transmission bandwidth. On the other hand, when the path
loss value is relatively small, the difference between UL frequency
band and DL frequency band is reduced. Namely when the path loss
value is relatively small, a frequency band allocated to the DL
transmission signal to the user equipment (UE) terminal is set
closer to the UL transmission bandwidth. This is because the UL
transmission power is small which is less likely to cause the
interference problem due to the uplink signal.
[0423] In the above example, it is assumed that the UL frequency is
lower than the DL frequency. Therefore, in a case where the UL
frequency is higher then the DL frequency, in an opposite manner,
when the path loss value is greater than the threshold value
Threshold.sub.DL,PL, a process is performed in which the RB groups
are sequentially allocated to the user equipment (UE) terminal in
the ascending order of the frequencies of the RB groups until the
number of the resource blocks allocated to the user equipment (UE)
terminal reaches the N.sub.allocated.sup.(RB) or more.
[0424] Further, in the above process, the order of performing the
steps S1110 through S1120 of the user equipment (UE) terminals
(i.e., order of "k" loop) is determined in step S1032 in which the
order is determined based on the order of "allocating the radio
resources to the user equipment (UE) terminals in accordance with
the Dynamic scheduling". However alternatively, the order of
performing the steps S1110 through S1120 of the user equipment (UE)
terminals (i.e., order of "k" loop) may be determined in accordance
with the descending order of the path loss values. More
specifically, the process of steps S1100 through S1120 is
sequentially performed in the descending order of the path loss
values of the user equipment (UE) terminals. In this case,
certainly, the frequency resources are sequentially allocated to
the user equipment (UE) terminals in the descending order of the
frequencies of the frequency resources in a manner so that the
larger the path loss value of the user equipment (UE) terminal is,
the more separated frequency resource from the uplink transmission
frequency is allocated, i.e., the higher frequency of the frequency
resource is allocated to the user equipment (UE) terminal. As a
result, it may become possible to improve the effect of reducing
the interference of the uplink transmission signal to the downlink
reception signal.
[0425] In the following, the RB group determined "to be allocated
to the user equipment (UE) terminal" in the processes of steps
S1208 and S1210 is called "Temporary RB group".
[0426] In step S1212, it is determined whether the logical channel
having the Highest priority includes retransmittable data.
[0427] When determining that the logical channel having the Highest
priority has retransmittable data (result of the determination in
step S1212 is YES), the process goes to step S1214. On the other
hand, when determining that the logical channel having the Highest
priority has no retransmittable data (result of the determination
in step S1212 is NO), the process goes to step S1213.
[0428] In step S1213, it is determined whether there is an HARQ
process for a new transmission. When determining that there is no
HARQ process for a new transmission (result of the determination in
step S1213 is NO), the process goes to step S1215.
[0429] In step S1214, among the retransmittable data (MAC PDU), the
data (MAC PDU) including RLC SDU having the maximum "buffer
residence time of the RLC SDU" of the logical channel having the
Highest priority are selected as the MAC PDU to be transmitted via
the subframe. Namely the data (MAC PDU) including RLC SDU having
the maximum "buffer residence time of the RLC SDU" of the logical
channel having the Highest priority are transmitted. Herein, the
definition of the "buffer residence time of the RLC SDU" is the
same as that of the RLC SDU buffer residence time described in No.
5 of Table 7.
[0430] In step S1215, among the retransmittable data (MAC PDU),
retransmission data (MAC PDU) having the highest priority level are
transmitted. Herein, the priority level refers to the priority
level of the Logical channel having the Highest priority among the
Logical Channels multiplexed to the retransmission data (MAC PDU).
Further, when there are plural retransmission data (MAC PDU) having
the highest priority level, the data (MAC PDU) including the RLC
SDU having the maximum "buffer residence time of the RLC SDU" of
the logical channel having the Highest priority are transmitted.
Herein, the definition of the "buffer residence time of the RLC
SDU" is the same as that of the RLC SDU buffer residence time
described in No. 5 of Table 7.
[0431] Further, in step S1216, the RB group and the modulation
scheme to be used for the transmission of the sub-frame are
determined. It is assumed that the RB group to be used for the
transmission of the sub-frame is the same as the Temporary RB
group. It is also assumed that the modulation scheme is the same as
that in the initial transmission. In the above example, a case is
described where the RB groups used for the data transmission
correspond to the Temporary RB groups. However, alternatively, when
the number of resource blocks included in the RB groups used for
the data transmission is greater than the number of resource blocks
allocated in the initial transmission, a process may be performed
in which some of the RB groups used for the transmission of the
sub-frame are not allocated until the number of resource blocks
reaches the number of resource blocks allocated in the initial
transmission.
[0432] Further, instead of assuming that the RB group to be used
for the transmission of the sub-frame is the same as the Temporary
RB group, based on the number of resource blocks in the RB groups,
the number of the resource blocks in the RB groups may be reduced.
Specifically, when the number of resource blocks in the Temporary
RB groups is greater than two times the number of the resource
blocks in the RB groups in the initial transmission, the number of
the resource blocks of the Temporary RB groups may be reduced so
that the number of the resource blocks of the Temporary RB groups
is less than two times the resource blocks in the RB groups in the
initial transmission. As the method of reducing the resource block
numbers, the same method as described in steps S1224 or S1232 may
be used. In the above example, two times is used. However, any
other factor such as one time, three times, or the like indicating
other than two times may also be used.
[0433] On the other hand, when determining that there is the HARQ
process for a new transmission (result of the determination in step
S1213 is YES), the process goes to step S1218.
[0434] In step S1218, a CQI value "CQI.sub.TFR" in the Temporary RB
group is calculated as described below.
[0435] When determining that the downlink transmission type is
Distributed, it is assumed that CQI.sub.TFR is defined as
CQI.sub.adjusted (all) (CQI.sub.TFR=CQI.sub.adjusted (all)). On the
other hand, when determining that the downlink transmission type is
not Distributed (i.e., Localized), it is assumed that CQI.sub.TFR
is obtained by true-value averaging the CQI.sub.adjusted with
respect each RB group in the Temporary RB group across the
bandwidth of the Temporary RB group (the averaging is required to
be performed by considering (the difference of) the number of
resource blocks of each RB groups).
[0436] Next, in step S1220, the data size ("Size") and the
modulation scheme ("Modulation") of the downlink shared channel
(DL-SCH) are determined by referring to TF_related_table using the
number (RB_available) of resource blocks in the Temporary RB group
and CQI.sub.TFR as arguments.
Size=DL_Table_TF_SIZE(RB_available,.left brkt-bot.CQI.sub.TFR.right
brkt-bot.)
Modulation=DL_Table_TF_Mod(RB_available,.left
brkt-bot.CQI.sub.TFR.right brkt-bot.) (16)
[0437] In step S1222, it is determined whether inequality
Size>N.sub.max,bit is satisfied (correct).
[0438] When determining that Size>N.sub.max,bit is satisfied
(result of determination in step S1222 is YES), the process goes to
step S1224, in which the number of resource blocks (RB available)
is reduced until inequality Size.ltoreq.N.sub.max,bit is satisfied.
Namely the number of resource blocks NUM.sub.RB to be allocated is
recalculated by referring to the TF_related_table using
N.sub.max,bit and CQI.sub.TFR as arguments.
Num.sub.RB=DL_Table_TF_RB(N.sub.max,bit,.left
brkt-bot.CQI.sub.TFR.right brkt-bot.) (17)
[0439] Then, when determining that the downlink transmission type
is Distributed, RB groups in the Temporary RB group are removed by
repeating the following process until the number of resource blocks
in the RB group to be used for the transmission is equal to or less
than NUM.sub.RB (removed RB groups are used as (k+1)th radio
resource or later).
Process: The RB groups are alternately removed from both of the RB
group having the smallest RB group Number and the RB group having
the greatest RB group Number.
[0440] The number of resource blocks in the Temporary RB group
after the above process is intended to be performed is defined as
Num.sub.RB. The above process is performed so that the remaining RB
groups after the removal of the RB groups can be discretely
distributed in the system bandwidth.
[0441] On the other hand, when determining that the downlink
transmission type is Localized, RB groups in the Temporary RB group
are removed by repeating the following process until the number of
resource blocks in the RB group to be used for the transmission is
equal to or less than NUM.sub.RB (removed RB groups are used as
(k+1)th radio resource or later).
Process: The RB group having the smallest CQI.sub.adjusted is
removed. When there are two or more RB groups having the smallest
CQI.sub.adjusted, the RB groups are sequentially removed in the
ascending order of the number of resource blocks in the RB groups.
When there are two or more RB groups having the smallest
CQI.sub.adjusted and having the smallest number of resource blocks,
the RB groups are sequentially removed in the descending order of
the RB group numbers of the RB groups.
[0442] The Temporary RB group after the above process is performed
is treated as the Temporary RB group in the following process; and
the number of the resource blocks in the Temporary RB group after
the above process is defined as Num.sub.RB. Further, the data size
("Size") and the modulation scheme ("Modulation") of the downlink
shared channel (DL-SCH) are determined again by referring to
TF_related_table using the number (RB_available) of resource blocks
in the Temporary RB group and CQI.sub.TFR as arguments.
Size=DL_Table_TF_SIZE(RB_available,.left brkt-bot.CQI.sub.TFR.right
brkt-bot.)
Modulation=DL_Table_TF_Mod(RB_available,.left
brkt-bot.CQI.sub.TFR.right brkt-bot.) (18)
[0443] After step S1224, the process goes to step S1226.
[0444] On the other hand, when determining that
Size.ltoreq.N.sub.max,bit is satisfied (result of determination in
step S1222 is NO), the process goes to step S1226.
[0445] Next, in step S1226, it is determined whether there are
sufficient data in the RLC Buffer.
[0446] When determining that there are sufficient data in the RLC
Buffer (result of determination in steps S1226 is YES), the process
goes to step S1228, in which, by the following procedures, the
control information of the MAC layer and the data of all logical
channels in the RLC Buffer are multiplexed with the MAC PDU having
the Size.
Step 1: First, when there is control information of the MAC layer,
the control information of the MAC layer is multiplexed with the
highest priority. Step 2: Next, the data in the RLC Buffer are
sequentially extracted and multiplexed in the descending order of
the priority levels of the logical channels. When there are two or
more logical channels having the same priority level, if there are
a DCCH, the DDCH is treated with the highest priority, and if there
is no DDCH, the data in the RLC buffer may be sequentially
extracted from the logical channels in any order. As a method of
selecting the logical channel in any order, the Round-Robin method
may be used.
[0447] Next, in step S1230, the RB group, the modulation scheme,
and the payload size to be used for the transmission of the
sub-frame are determined. Specifically, the RB group to be used for
the data transmission is same as the Temporary RB group. The
modulation scheme to be used for the data transmission is the same
as the Modulation. The payload size is the same as the Size.
[0448] On the other hand, when determining that there are no
sufficient data in the RLC Buffer (result of determination in steps
S1226 is NO), the process goes to step S1232, in which, until
inequality Size.ltoreq.Size.sub.all is satisfied, the number of
resource blocks to be allocated is reduced. Herein, the symbol
Size.sub.all denotes total size of the data in the RLC buffer of
the MAC control block and all the Logical channels. The processing
method is described in more detail below.
[0449] First, the number NUM.sub.RB of resource blocks to be
allocated is recalculated by referring to the TF_related_table
using the total size "Size.sub.all" of the data in the RLC buffer
of the MAC control block and all the logical channels and the
"CQI.sub.TFR" as arguments.
Num.sub.RB=DL_Table_TF_RB(Size.sub.all,.left
brkt-bot.CQI.sub.TFR.right brkt-bot.) (19)
[0450] When determining that the downlink transmission type is
Distributed, the RB groups in the Temporary RB group are removed by
repeating the following process as long as the number of RB groups
to be used for transmission is equal to or greater than the
NUM.sub.RB.
Process: Among the RB groups in the Temporary RB group, the RB
groups are sequentially and alternately removed from both the RB
group having the greatest RB group number and the RB group having
the smallest RB group number.
[0451] The Temporary RB group after the above process is used as
the Temporary RB group in the following process. Further, the
number of resource blocks in the Temporary RB group is defined as
Num.sub.RB,F.
[0452] When determining that the downlink transmission type is not
Distributed, namely when determining that the downlink transmission
type is Localized, the RB groups in the Temporary RB group are
removed by repeating the following process as long as the number of
RB groups to be used for transmission is equal to or greater than
the NUM.sub.RB.
Process: The RB groups are sequentially removed in the ascending
order of the CQI.sub.adjusted values of the RB groups. When there
are two or more RB groups having the smallest CQI.sub.adjusted
value, the RB groups are sequentially removed in the ascending
order of the number of resource blocks of the RB groups. When there
are two or more RB groups having the smallest CQI.sub.adjusted
value and having the smallest number of resource blocks, the RB
groups are sequentially removed in the descending order of the RB
group numbers of the RB groups.
[0453] The Temporary RB group after the above process is used as
the Temporary RB group in the following process. Further, the
number of resource blocks in the Temporary RB group is defined as
Num.sub.RB,F.
[0454] The removed RB groups in the above processes are used as
(k+1)th radio resource or later.
[0455] Further, the data size ("Size") and the modulation scheme
("Modulation") of the downlink shared channel (DL-SCH) are
determined again by referring to TF_related_table using the number
(Num.sub.RB,F) of resource blocks in the Temporary RB group and
CQI.sub.TFR as arguments.
Size=DL_Table_TF_SIZE(Num.sub.RB,F,.left brkt-bot.CQI.sub.TFR.right
brkt-bot.)
Modulation=DL_Table_TF_Mod(Num.sub.RB,F,.left
brkt-bot.CQI.sub.TFR.right brkt-bot.) (20)
[0456] Further, in step S1234, the control information of the MAC
layer and the data of all logical channels in the RLC Buffer are
multiplexed with the MAC PDU having the Size.
[0457] Next, in step S1230, the RB group, the modulation scheme,
and the payload size to be used for the transmission of the
sub-frame are determined. Namely the RB group to be used for the
data transmission is the same as the Temporary RB group. The
modulation scheme to be used for the data transmission is the same
as the Modulation. The payload size is the same as the Size.
[0458] The RLC buffer described in the above examples is generally
a data buffer. Further, the same above processes may be performed
on not the RLC buffer but the PDCP buffer.
[0459] In step S1116, the RV selection (Redundancy Version
Selection) process is performed.
[0460] In step S1118, the value of "k" may be incremented, and in
step S1120, it may be determined whether the value of "k" is equal
to or less than N.sub.DL-SCH. when determining that the value of
"k" is equal to or less than N.sub.DL-SCH (YES in step S1120), the
process may go back to step S1112. On the other hand, when
determining that the value of "k" is not equal to or less than
N.sub.DL-SCH (NO in step S1120), the process may terminate.
[0461] Next, the base station apparatus 200 according to an
embodiment of the present invention is described with reference to
FIG. 13.
[0462] As shown in FIG. 13, the base station apparatus 200
according to an embodiment of the present invention includes a
layer 1 processing section 252, a user equipment status management
section 254, a scheduling coefficient counting section 256, a UE
selection section 258, a TFR (Transport Format Resource block)
Selection section 268, an MAC control signal generation section
260, a common channel/MCH resource management section 262, a
frequency resource management section 264, a persistent resource
management section 266, an HARQ control section 270, and an
RLC/PDCP processing section 272. The HARQ control section 270
includes HARQ.sub.1 control section 270, HARQ.sub.2 control section
270, . . . , and HARQ.sub.n control section 270 corresponding to
UE(user equipment terminal)#1, UE#2, and UE#n, respectively. The
RLC/PDCP processing section 272 includes RLC Bufs 2722.sub.1,1
through 2722.sub.1,k for logical channels #1 through #k of UE#1,
RLC Bufs 2722.sub.2,1 through 2722.sub.2,k for logical channels #1
through #k of UE#2, . . . , RLC Bufs 2722.sub.n,1 through
2722.sub.n,k for logical channels #1 through #k of UE#n,
respectively.
[0463] In FIG. 13, the base station apparatus 200 includes one HARQ
control section with respect to each UE (i.e., n.times.HARQ for
n.times.UE). However alternatively, the base station apparatus 200
may include only one HARQ control section for all or plural UEs.
Further, it is not always necessary to provide one RLC BUf for each
logical channel of each UE. Alternatively, one RLC Buf may be
provided for one UE or all UEs.
[0464] The layer 1 processing section 252 performs processes
related to the layer 1. More specifically, the layer 1 processing
section 252 performs, for example, a channel coding process and an
IFFT process on the shared channel transmitted in downlink and a
reception process such as an FFT process and a channel decoding
process on the shared channel transmitted in uplink. The shared
channel transmitted in uplink refers to, for example, a shared
channel to which the Dynamic Scheduling is applied and a shared
channel to which the Persistent Scheduling is applied.
[0465] Further, the layer 1 processing section 252 performs the
transmission of the Downlink Scheduling Information and the Uplink
Scheduling Grant, the Downlink Scheduling Information being control
information for the downlink shared channel (DL-SCH), the Uplink
Scheduling Grant being control information for the uplink shared
channel (UL-SCH).
[0466] Further, the layer 1 processing section 252 performs the
reception of control information transmitted in uplink, i.e., the
control information including the CQI (Channel Quality Information)
and the acknowledgement information with respect to the downlink
shared channel. Such CQI and the acknowledgement information are
transmitted to the user equipment status management section
254.
[0467] Further, the layer 1 processing section 252 detects uplink
synchronization status based on the Sounding reference signal
transmitted in uplink and the CQI signal and reports the detection
result to the user equipment status management section 254.
[0468] Further, the layer 1 processing section 252 may estimate
uplink reception timings based on the Sounding reference signal
transmitted in uplink and the CQI signal and reports the estimation
result of the uplink reception timings to the MAC control signal
generation section 260 via, for example, the user equipment status
management section 254.
[0469] Further, the layer 1 processing section 252 is connected to
a radio interface. More specifically, in downlink, the baseband
signal generated in the layer 1 processing section 252 is converted
into a signal in radio frequency band. Then the converted signal is
amplified in the amplifier and transmitted to user equipment (UE)
via an antenna. On the other hand, in uplink, a radio-frequency
signal received by the antenna is amplified in the amplifier,
frequency-converted into a baseband signal, and is input to the
layer 1 processing section 252.
[0470] The user equipment status management section 254 performs
status management of the user equipment (UE) terminals. For
example, the equipment status management section 254 performs
status management of HARQ Entity, management and control of
Mobility of UE, manages DRX status and uplink synchronization,
whether Persistent scheduling is to be applied, whether MAC Control
Block is to be transmitted, the downlink transmission status, and a
buffer status. Further, in step S1024, the equipment status
management section 254 calculates metrics necessary for the
calculation of the Scheduling Coefficient and determines whether
the Scheduling Coefficient is to be calculated. Namely the
equipment status management section 254 performs processes in steps
S1004 through S1022 in FIG. 10.
[0471] The Mobility of the UE described above refers to a handover
switching a cell to which the UE is to be communicated, the
handover including handover between the same frequency, between
different frequencies, and between different systems. In cases of
the handover between the different frequencies or between different
systems, the management and control of the Management Gap is
included in the management and control of Mobility of UE.
[0472] Further, the equipment status management section 254
performs the processes of steps S902, S904, and S906. More
specifically, the equipment status management section 254 sets the
maximum multiplexing number per a sub-frame with respect to the DL
MAC of the sub-frame, counts the numbers of MCH, D-BCH, PCH, RACH
response and RACH message4 in the sub-frame.
[0473] The scheduling coefficient counting section 256 performs the
processes of steps S1002 and S1024 through S1032 in FIG. 10. More
specifically, the scheduling coefficient counting section 256
calculates the scheduling coefficients of the user equipment (UE)
terminals in the sub-frame (see FIG. 11). On the other hand, the UE
selection section 258 selects the user equipment (UE) terminals to
which radio resources are allocated based on the Dynamic scheduling
based on the calculated Scheduling Coefficients. The UE selection
section 258 reports the number "N.sub.DL-SCH" of the user equipment
(UE) terminals to which radio resources are allocated based on the
Dynamic scheduling to the TFR (Transport Format Resource block)
Selection section 268.
[0474] The TFR Selection section 268 performs the processes of
steps S1110, S1112, S1114, S1116, and S1120. More specifically, the
TFR Selection section 268 determines the transmission formats and
allocates radio resources related to the downlink shared channel
(DL-SCH) to which the Dynamic Scheduling is applied. The
information of the transmission formats and radio resources related
to the downlink shared channel (DL-SCH) to which the Dynamic
Scheduling is applied determined by the TFR Selection section 268
is transmitted to the layer 1 processing section 252 to be used for
the transmission processes of the DL Scheduling Information and the
downlink shared channel (DL-SCH) in the layer 1 processing section
252.
[0475] The common channel/MCH resource management section 262
determines the transmission formats and allocates the radio
resources for the MCH and common channels such as Synchronization
channel (SCH), Primary Broadcast Channel (P-BCH), Dynamic Broadcast
Channel (D-BCH), Paging Channel (PCH), Random Access Channel
response (RACH response), and PACH message4. The common channel/MCH
resource management section 262 reports the frequency resources
among the radio resources to the frequency resource management
section 264. The information of the transmission formats and
allocated radio resources determined by the common channel/MCH
resource management section 262 is transmitted to the layer 1
processing section 252 via the frequency resource management
section 264 and the TFR Selection section 268, so that layer 1
processes of the MCH and the Common Channels are performed in the
layer 1 processing section 252.
[0476] The frequency resource management section 264 is connected
to the TFR Selection section 268, the common channel/MCH resource
management section 262, and the persistent resource management
section 26 and performs the management of the frequency resources.
More specifically, the frequency resource management section 264
monitors remaining frequency resources usable for the downlink
shared channel (Dl-SCH) to which Dynamic Scheduling is applied and
provides information necessary for the process of step S1110 to the
TFR Selection section 268.
[0477] The persistent resource management section 266 performs the
status management of the downlink shared channel (DL-SCH) to which
the Persistent Scheduling is applied and manages the radio
resources. More specifically, the persistent resource management
section 266 determines the transmission formats related to the
downlink shared channel (DL-SCH) to which the Persistent Scheduling
is applied and manages the radio resources. Further, the persistent
resource management section 266 reports the frequency resources
among the radio resources to the frequency resource management
section 264. The information of the transmission formats and
allocated radio resources determined by persistent resource
management section 266 is transmitted to the layer 1 processing
section 252 via the frequency resource management section 264 and
the TFR Selection section 268, so that the process of the layer 1
of downlink shared channel (DL-SCH) to which the Persistent
Scheduling is applied is performed in the layer 1 processing
section 252.
[0478] Further, the persistent resource management section 266
sends the information necessary to perform the processes of steps
S1012 through S1016 performed in the equipment status management
section 254 to the equipment status management section 254.
[0479] The MAC control signal generation section 260 determines
whether the MAC control signal is to be transmitted to each user
equipment (UE) terminal, and when determining that the MAC control
signal is to be transmitted, reports the result of determination to
the equipment status management section 254. Further, when the MAC
control signal is to be actually mapped, the MAC control signal
generation section 260 sends the MAC control signal to the TFR
Selection section 268.
[0480] The MAC control signal includes, for example, a control
signal instructing the timing advance for adjusting the
transmission timing of the uplink signal and the establishment of
the uplink synchronization and a control signal instructing to go
into DRX mode. Whether each of the control signals is to be
transmitted is determined based on the information from the
equipment status management section 254 or the layer 1 processing
section 252.
[0481] The HARQ.sub.n control section 270 performs the control with
respect to the HARQ of each user equipment (UE) terminal.
[0482] The RLC/PDCP processing section 272 performs the control of
the RLC layer and the PDCP layer of each user equipment (UE)
terminal. Further, the RLC/PDCP processing section 272 includes RLC
Buf2721.sub.n,k which is the RLC Buffer related to the logical
channel #k of UE #n so as to buffer the data of the PDCP layer to
be transmitted in downlink.
[0483] In the above example, the RLC BUf2721.sub.n,k buffers the
data of the RLC layer. However alternatively, the RLC
BUf2721.sub.n,k may buffer the data of the RLC layer and the PDCP
layer as well.
[0484] Namely, the data transmitted via the downlink shared channel
(DL-SCH) in the sub-frame are extracted by the RLC BUf2721.sub.n,k
in the RLC/PDCP processing section 272, HARQ-processed in the
HARQ.sub.n control section 270, and transmitted to the layer 1
processing section 252 via the UE selection section 258 and the TFR
Selection section 268, so that the transmission processes such as
coding, IFFT, and the like in the layer 1 processing section
252.
[0485] The present invention is described above by referring to
specific embodiments. However, it should not be understood that the
descriptions and figures constituting the parts of the disclosure
limit the present invention. Based on the disclosure, a person
skilled in the art may think of examples of various modifications,
transformations, alterations, operational technique, and the
like.
[0486] For example, in the above embodiments, a system in which
Evolved UTRA and UTRAN (a.k.a. Long term Evolution or Super 3G) is
applied is described. However, a mobile station (user equipment
(UE) terminal), a base station apparatus, a mobile communication
system, and communication control method according to an embodiment
of the present invention may also be applied to any other system
capable of communicating using the shared channel.
[0487] Namely obviously, the present invention includes various
embodiments not described herein. Therefore, a technical scope of
the present invention is defined only by the invention specifying
matters according to adequate scopes of the claims based on the
descriptions.
[0488] For explanation purpose, plural embodiments are separately
described. However, such separation of the embodiments is not
essential to the present invention, and two or more embodiments may
be used on an as needed basis.
[0489] Further, for explanation purpose, specific values are used
to promote understanding the present invention. However, unless
otherwise described, the values are for illustrative purpose only
and any other suitable values may be used.
[0490] The present invention is described above by referring to
specific embodiments. However, a person skilled in the art may
understand that the above embodiments are described for
illustrative purpose only and may think of examples of various
modifications, transformations, alterations, changes, and the like.
For illustrative purposes, the apparatus according to an embodiment
of the present invention is described with reference to the
functional block diagram. However, such an apparatus may be
provided by hardware, software, or a combination thereof. The
present invention is not limited to the embodiment described above,
and various modifications, transformations, alteration, exchanges,
and the like may be made without departing from the scope and
spirit from the present invention.
[0491] The present international application claims priority from
Japanese Patent Application Nos. 2007-052115 filed on Mar. 1, 2007,
2007-161938 filed on Jun. 19, 2007, and 2007-329024 filed on Dec.
20, 2007, the entire contents of which Japanese Patent Application
Nos. 2007-052115, 2007-161938, and 2007-329024 are hereby
incorporated herein by reference.
* * * * *