U.S. patent application number 15/363224 was filed with the patent office on 2017-03-16 for mobile communication method and radio base station.
This patent application is currently assigned to NTT DOCOMO, INC.. The applicant listed for this patent is NTT DOCOMO, INC.. Invention is credited to Mikio Iwamura, Anil Umesh.
Application Number | 20170078057 15/363224 |
Document ID | / |
Family ID | 47176829 |
Filed Date | 2017-03-16 |
United States Patent
Application |
20170078057 |
Kind Code |
A1 |
Iwamura; Mikio ; et
al. |
March 16, 2017 |
MOBILE COMMUNICATION METHOD AND RADIO BASE STATION
Abstract
Transmission/reception timing of a data signal and a control
signal through a Uu interface and transmission/reception timing of
the data signal through a Ud interface are properly adjusted. A
mobile communication method according to the present invention
includes: a step A in which a radio base station eNB notifies a
mobile station UE#1 and a mobile station UE#2 that an opportunity
to transmit and receive the data signal through the Ud interface is
allocated through a PDCCH in which an X-RNTI is used; and a step B
in which the radio base station eNB transmit "direction
information", for notifying of a direction in which the data signal
should be transmitted in the opportunity, to the mobile station
UE#1 and the mobile station UE#2.
Inventors: |
Iwamura; Mikio; (Tokyo,
JP) ; Umesh; Anil; (Tokyo, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
NTT DOCOMO, INC. |
Tokyo |
|
JP |
|
|
Assignee: |
NTT DOCOMO, INC.
Tokyo
JP
|
Family ID: |
47176829 |
Appl. No.: |
15/363224 |
Filed: |
November 29, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14118299 |
Jan 8, 2014 |
9544106 |
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PCT/JP2012/061941 |
May 10, 2012 |
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15363224 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04W 72/0406 20130101;
H04L 5/0037 20130101 |
International
Class: |
H04L 5/00 20060101
H04L005/00; H04W 72/04 20060101 H04W072/04 |
Foreign Application Data
Date |
Code |
Application Number |
May 18, 2011 |
JP |
2011-111921 |
Claims
1. A mobile communication method for transmitting and receiving a
data signal and a control signal through a radio base station
interface between a first mobile station and a second mobile
station and a radio base station, and for transmitting and
receiving the data signal through an inter-mobile station interface
between the first mobile station and the second mobile station, the
mobile communication method comprising: a step A in which the radio
base station notifies the first mobile station and the second
mobile station that an opportunity to transmit and receive the data
signal through the inter-mobile station interface is allocated
through a physical downlink control channel in which common
identification information is used; and a step B in which the radio
base station transmits transmission direction information through
RRC signaling, for notifying of a direction in which the data
signal should be transmitted in the opportunity, to the first
mobile station and the second mobile station.
2. A radio base station that is used in a mobile communication
system configured to be able to transmit and receive a data signal
and a control signal through a radio base station interface between
a first mobile station and a second mobile station and a radio base
station, and to transmit and receive the data signal through an
inter-mobile station interface between the first mobile station and
the second mobile station, the radio base station comprising a
transmission unit configured to notify the first mobile station and
the second mobile station that an opportunity to transmit and
receive the data signal through the inter-mobile station interface
is allocated through a physical downlink control channel in which
common identification information is used, wherein the transmission
unit is configured to transmit transmission direction information
through RRC signaling, for notifying of a direction in which the
data signal should be transmitted in the opportunity, to the first
mobile station and the second mobile station.
3. The radio base station according to claim 2, wherein the
transmission direction information is tied to a periodic time
resource and frequency resource.
4. The radio base station according to claim 2, wherein the
transmission unit is configured to notify of a frequency, at which
the data signal should be transmitted and received through the
inter-mobile station interface, through the physical downlink
control channel.
5. The radio base station according to claim 2, wherein the
transmission unit is configured to notify of a frequency, at which
the data signal should be transmitted and received through the
inter-mobile station interface, through RRC signaling.
6. The radio base station according to claim 2, wherein the
transmission unit is configured to notify of a subframe, to which
the data signal should be transmitted and received through the
inter-mobile station interface, through the physical downlink
control channel.
7. The radio base station according to claim 2, wherein the
transmission unit is configured to transmit time-division
information necessary to transmit and receive the data signal and
the control signal through the radio base station interface and
transmit and receive the data signal through the inter-mobile
station interface in a time-division manner, through RRC
signaling.
8. The radio base station according to claim 2, wherein the
transmission unit is configured such that a format of the physical
downlink control channel, for notifying that the opportunity to
transmit and receive the data signal through the radio base station
interface is allocated, is different from a format of physical
downlink control channel, for notifying that the opportunity to
transmit and receive the data signal through the inter-mobile
station interface is allocated.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This is a continuation application of U.S. patent
application Ser. No. 14/118,299 filed Nov. 18, 2013, which is a
national stage application of PCT/JP2012/061941 filed May 10, 2012,
which claims priority to Japanese Patent Application No.
2011-111921 filed May 18, 2011. The content of these applications
is incorporated by reference in their entirety.
TECHNICAL FIELD
[0002] The present invention relates to a mobile communication
method and a radio base station.
BACKGROUND ART
[0003] FIG. 7 illustrates transmission/reception tiding in a Uu
interface (radio base station interface) of a conventional LTE
(Long Term Evolution) system.
[0004] In an example in FIG. 7, at a frequency F1, a mobile station
UE is configured to receive a control signal through a PDCCH
(Physical Downlink Control Channel), and to receive a data signal
through a PDSCH (Physical Downlink Shared Channel).
[0005] The mobile station UE is also configured to transmit the
data signal through a PUSCH (Physical Uplink Shared Channel) at a
frequency F2.
[0006] A radio base station eNB is configured to transmit a "DL
resource allocation" notifying of an allocation of an opportunity
(Uu DL) to receive the data signal through the Uu interface (PDSCH)
and a "UL grant" notifying of an allocation of an opportunity (Uu
UL) to transmit the data signal through the Uu interface (PUSCH)
through the PDCCH.
[0007] The "Uu DL" is allocated on a subframe identical to the
PDCCH.
[0008] On the other hand, the subframe to which the "Uu UL" is
allocated is determined in consideration of a processing delay
until the data signal (transport block) is generated from the time
when the "UL grant" is received through the PDCCH in the mobile
station UE.
[0009] For example, the "Uu UL" is configured to be allocated to
the subframe located behind the subframe, to which the PDCCH is
allocated, by X subframes.
CITATION LIST
Non-Patent Literature
[0010] Non-Patent Literature 1: 3GPP TS36.300
[0011] Non-Patent Literature 2: 3GPP TS36.323
[0012] Non-Patent Literature 3: 3GPP TS36.213
SUMMARY OF INVENTION
[0013] In the future, in the LTE mobile communication system, there
is a possibility that a mobile station UE#1 and a mobile station
UE#2 that are in an "RRC_Connected state" in a cell under control
of the identical radio base station eNB can perform the
transmission/reception of the data signal through the Ud interface
(inter-mobile station interface) that is directly set between the
mobile station UE#1 and the mobile station UE#2 in addition to the
transmission/reception of the data signal and the control signal
between the mobile station UE#1 and the mobile station UE#2 and the
radio base station eNB through the Uu interface.
[0014] However, in such cases, the mobile station UE#1 and the
mobile station UE#2 cannot simultaneously perform the
transmission/reception of the data signal and the control signal
through the Uu interface and the transmission/reception of the data
signal through the Ud interface at an identical frequency.
Therefore, it is inevitable to adjust transmission/reception timing
of the data signal and the control signal through the Uu interface
and transmission/reception timing of the data signal through the Ud
interface.
[0015] The present invention has been devised to solve the above
problems, and an object thereof is to provide a mobile
communication method and a radio base station, which can properly
adjust the transmission/reception timing of the data signal and the
control signal through the Uu interface and the
transmission/reception timing of the data signal through the Ud
interface.
[0016] In accordance with a first aspect of the present invention,
a mobile communication method for transmitting and receiving a data
signal and a control signal through a radio base station interface
between a first mobile station and a second mobile station and a
radio base station, and for transmitting and receiving the data
signal through an inter-mobile station interface between the first
mobile station and the second mobile station, the mobile
communication method includes: a step A in which the radio base
station notifies the first mobile station and the second mobile
station that an opportunity to transmit and receive the data signal
through the inter-mobile station interface is allocated through a
physical downlink control channel in which common identification
information is used; and a step B in which the radio base station
transmits transmission direction information, for notifying of a
direction in which the data signal should be transmitted in the
opportunity, to the first mobile station and the second mobile
station.
[0017] In accordance with a second aspect of the present invention,
a radio base station that is used in a mobile communication system
configured to be able to transmit and receive a data signal and a
control signal through a radio base station interface between a
first mobile station and a second mobile station and a radio base
station, and to transmit and receive the data signal through an
inter-mobile station interface between the first mobile station and
the second mobile station, the radio base station including a
transmission unit configured to notify the first mobile station and
the second mobile station that an opportunity to transmit and
receive the data signal through the inter-mobile station interface
is allocated through a physical downlink control channel in which
common identification information is used, wherein the transmission
unit is configured to transmit transmission direction information,
for notifying of a direction in which the data signal should be
transmitted in the opportunity to the first mobile station and the
second mobile station.
BRIEF DESCRIPTION OF DRAWINGS
[0018] FIG. 1 is an entire configuration diagram of a mobile
communication system according to a first embodiment of the present
invention.
[0019] FIG. 2 is a functional block diagram of a radio base station
according to the first embodiment of the present invention.
[0020] FIG. 3 is a view illustrating transmission/reception timing
in the mobile communication system according to the first
embodiment of the present invention.
[0021] FIG. 4 is a view illustrating the transmission/reception
timing in the mobile communication system according to the first
embodiment of the present invention.
[0022] FIG. 5 is a view illustrating the transmission/reception
timing in the mobile communication system according to the first
embodiment of the present invention.
[0023] FIG. 6 is a view illustrating the transmission/reception
timing in the mobile communication system according to the first
embodiment of the present invention.
[0024] FIG. 7 is a view explaining a conventional mobile
communication system.
DESCRIPTION OF EMBODIMENTS
Mobile Communication System According to a First Embodiment of the
Present Invention
[0025] A mobile communication system according to the first
embodiment of the present invention will be described with
reference to FIGS. 1 to 6.
[0026] The mobile communication system of the embodiment is an LTE
mobile communication system, and includes a core network (not
illustrated) and a radio base station eNB connected to the core
network as illustrated in FIG. 1. The present invention can also be
applied to a cellular mobile communication system in addition to
the LTE mobile communication system.
[0027] As illustrated in FIG. 1, a mobile station UE#1 is
configured to transmit and receive a data signal and a control
signal to and from the radio base station eNB through a Uu
interface, and to transmit and receive the data signal to and from
a mobile station UE#2 through a Ud interface.
[0028] Similarly, the mobile station UE#2 is configured to transmit
and receive the data signal and the control signal to and from the
radio base station eNB through the Uu interface, and to transmit
and receive the data signal to and from the mobile station UE#1
through the Ud interface.
[0029] As illustrated in FIG. 2, the radio base station eNB
includes an allocation unit 11, a transmission unit 12, and a
reception unit 13.
[0030] The allocation unit 11 is configured to allocate an
opportunity transmit and receive the data signal to and from the
mobile station UE#1 and the mobile station UE#2 through the Uu
interface or an opportunity to transmit and receive the data signal
to and from the mobile station UE#1 and the mobile station UE#2
through the Ud interface.
[0031] The transmission unit 12 is configured to transmit the data
signal and the control signal to the mobile station UE#1 and one
mobile station UE# 2 through the Uu interface.
[0032] For example, the transmission unit 12 is configured to
transmit a "DL resource allocation" to the mobile station UE#1 and
the mobile station UE#2 through a PDCCH in which identification
information (C-RNTI: Cell-Radio Network Temporary Identity) is
used, and the transmission unit 12 is configured to transmit a "UL
grant" to the mobile station UE#1 and the mobile station UE#2
through the Uu interface (PUSCH). The "DL resource allocation"
notifies the mobile station UE#1 and the mobile station UE#2 that
the opportunity (Uu DL) to receive the data signal through the Uu
interface (PDSCH) is allocated to the control signal. The "UL
grant" notifies the mobile station UE#1 and the mobile station UE#2
that the opportunity (Uu UL) to transmit the data signal through
the Uu interface (PUSCH).
[0033] The transmission unit 12 is configured to notify the mobile
station UE#1 and the mobile station UE#2 that the opportunity (Ud
Tx) to transmit the data signal through the Ud interface is
allocated through the PDCCH in which common identification
information (hereinafter referred to as an X-RNTI) on the mobile
station UE#1 and the mobile station UE#2 is used, and to notify the
mobile station UE#1 and the mobile station UE#2 that the
opportunity (Ud Rx) to receive the data signal through the Ud
interface is allocated.
[0034] At this point, in making the notification that the "Ud Tx"
and the "Ud Rx" are allocated, the use of the X-RNTI common to the
mobile station UE#1 and the mobile station UE#2 can reduce a
signaling amount related to the PDCCH compared with the case where
a C-RNTI is used in each of the mobile station UE#1 and the mobile
station UE#2.
[0035] The transmission unit 12 may be configured to previously
allocate the X-RNTI to the mobile station UE#1 and the mobile
station UE#2 through RRC signaling. The mobile station UE#1 and the
mobile station UE#2 may be notified of the X-RNTI during a setting
of the Ud interface.
[0036] The transmission unit 12 is also configured to transmit the
data signal to the mobile station UE#1 and the mobile station UE#2
through the PDSCH in the opportunity allocated by the allocation
unit 11.
[0037] Therefore, each of the mobile station UE#1 and the mobile
station UE#2 performs "blind decode" to the PDCCH that is
transmitted using the X-RNTI while performing the "blind decode" to
the PDCCH that is transmitted using the C-RNTI of itself.
[0038] The reception unit 13 is configured to receive the data
signal and the control signal from the mobile station UE#1 and the
mobile station UE#2 through the Uu interface.
[0039] For example, the transmission unit 12 is configured to
receive the data signal from the mobile station UE#1 and the mobile
station UE#2 through the PUSCH in the opportunity allocated by the
allocation unit 11.
[0040] In the mobile communication system of the embodiment, the
following four cases are considered by a combination of a frequency
used in the transmission/reception through the Uu interface and a
frequency used in the transmission/reception through the Ud
interface.
[0041] The case where the frequency used in the
transmission/reception through the Ud interface is the same as the
frequency used in the transmission/reception of an uplink through
the Uu interface (case 1)
[0042] The case where the frequency used in the
transmission/reception through the Ud interface is to the same as
the frequency used in the transmission/reception of a downlink
through the Uu interface (case 2)
[0043] The case where the frequency used in the
transmission/reception through the Ud interface is different from
the frequency used in the transmission/reception through the Uu
interface while the frequency used in the transmission/reception
through the Ud interface is to the same as the frequency used in
the transmission of the mobile station UE#2 through the Ud
interface (case 3)
[0044] The case where the frequency used in the
transmission/reception through the Ud interface is different from
the frequency used in the transmission/reception through the Uu
interface while the frequency used in the transmission of the
mobile station UE#1 through the Ud interface is different from the
frequency used in the transmission of the mobile station UE#2
through the Ud interface (case 4)
[0045] The transmission/reception timing through the Uu interface
and the transmission/reception timing Uu interface Ud interface in
the cases 1 to 4 will be described with reference to FIGS. 3 to
6.
[0046] In examples in FIGS. 3 to 6, a head position of each
subframe at a frequency F1 and a head position of each subframe at
a frequency F2 are identical to each other (when viewed from the
radio base station eNB). However, the present invention can also be
applied to the case where the head positions of each subframe at
the frequencies F1 and F2 are not identical to each other.
[0047] <Case 1>
[0048] As illustrated in FIG. 3, in the case 1, the
transmission/reception through the Ud interface and the
transmission/reception of the uplink through the Uu interface are
configured to be performed in a time-division manner at the
frequency F2.
[0049] As illustrated in FIG. 3, in the case 1, the
transmission/reception of the downlink through the Uu interface is
configured to be performed at the frequency F1.
[0050] Specifically, the allocation unit 11 is configured to
perform the allocation similar to that of the conventional LTE
system to the opportunity to perform the transmission/reception of
the uplink through the Uu interface and the opportunity to perform
the transmission/reception of the downlink through the Uu
interface.
[0051] That is, the allocation unit 11 is configured to allocate
the PDSCH (that is, the "Uu DL") to the subframe identical to that
of the PDCCH, and to allocate the PUSCH (that is, the "Uu UL") to
the subframe that is located behind the subframe, to which the
PDCCH is allocated, by X subframes.
[0052] On the other hand, the allocation unit 11 is configured to
determine the opportunity to perform the transmission/reception
through the Ud interface in consideration of a processing delay
until the data signal (transport block) is generated in the mobile
station UE#1 and the mobile station UE#2.
[0053] For example, the allocation unit 11 is configured to
allocate the opportunity to perform the transmission/reception
through the Ud interface co the sub frame that is located behind
the subframe, to which the PDCCH is allocated, by Y (X.ltoreq.Y)
subframes.
[0054] The transmission unit 12 may be configured to transmit
"direction information (for example, UE#1.fwdarw.UE#2 or
UE#2.fwdarw.UE#1)", for notifying a direction in which the data
signal should be transmitted in the opportunity (subframe) to
perform the transmission/reception through the Ud interface, to the
mobile station UE#1 and the mobile station UE#2 through the
PDCCH.
[0055] Alternatively, the transmission unit 12 may be configured to
previously transmit and set the "direction information" notifying
the mobile station UE#1 and the mobile station UE#2 of the
direction in which the data signal should be transmitted in each
subframe to the mobile station UE#1 and the mobile station UE#2
through the RRC signaling. In such cases, the transmission unit 12
needs not to include the "direction information" in the PDCCH.
[0056] The transmission unit 12 may be configured to transmit
time-division information to the mobile station UE#1 and the mobile
station UE#2 through the RRC signaling. The time-division
information is necessary to perform the transmission/reception
through the Uu interface and the transmission/reception through the
Ud interface in the time-division manner.
[0057] For example, the transmission unit 12 is configured to
transmit information, which notifies of the subframe to which the
opportunity to perform the transmission/reception through the Uu
interface is possibly allocated and the subframe to which the
opportunity to perform the transmission/reception through the Ud
interface is possibly allocated, as time-division information.
[0058] Thus, in the case where the time-division information is
previously transmitted through the RRC signaling, the mobile
station UE#1 and the mobile station UE#2 may perform the "blind
decode" while being limited to a "DL resource allocation"
transmitting PDCCH format and a "UL grant" transmitting PDCCH
format, in the subframe (for example, subframes #1, #3, and #5) to
which the opportunity to perform the transmission/reception through
the Uu interface is possibly allocated.
[0059] Similarly, in the case where the time-division information
is previously transmitted through the RRC signaling, the mobile
station UE#1 and the mobile station UE#2 may perform the "blind
decode" while being limited to the "DL resource allocation"
transmitting PDCCH format, a PDCCH format notifying that the
opportunity to perform the transmission/reception
(UE#1.fwdarw.UE#2) through the Ud interface is allocated, and a
PDCCH format notifying that the opportunity to perform the
transmission/reception (UE#2.fwdarw.UE#1) through the Ud interface
is allocated, in the subframe (for example, subframes #2, #4, and
#6) to which the opportunity to perform the transmission/reception
through the Ud interface is possibly allocated.
[0060] At this point, the PDCCH format notifying that the
opportunity to perform the transmission/reception through the Uu
interface is allocated may be configured to be different from the
PDCCH format notifying that she opportunity to perform the
transmission/reception through the Ud interface is allocated.
[0061] In the PDCCH formats, for notifying that the opportunity to
perform the transmission/reception through the Uu interface is
allocated, the "DL resource allocation" transmitting PDCCH format
may be configured to be different from the "UL grant" transmitting
PDCCH format.
[0062] The PDCCH format notifying that the opportunity to perform
the transmission/reception (UE#.fwdarw.UE#2) through the Ud
interface is allocated may be configured to be different from the
PDCCH format notifying that the opportunity to perform the
transmission/reception (UE#2.fwdarw.UE#1) through the Ud interface
is allocated.
[0063] As a result, the number of patterns of the "blind decode"
performing PDCCH format in the mobile station UE#1 and the mobile
station UE#2 can be decreased.
[0064] In the case where the "direction information" is previously
transmitted through the RRC signaling in addition to the
time-division information, the mobile station UE#1 and the mobile
station UE#2 may perform the "blind decode" in each subframe while
being limited to one of a combination of the "DL resource
allocation" transmitting PDCCH format and the "UL grant"
transmitting PDCCH format, a combination of the "DL resource
allocation" transmitting PDCCH format and the PDCCH format
notifying that the opportunity to perform the
transmission/reception (UE#1.fwdarw.UE#2) through the Ud interface
is allocated, and a combination of "DL resource allocation"
transmitting PDCCH format and the PDCCH format notifying that the
opportunity to perform the transmission/reception (UE#2 UE#1)
through the Ud interface is allocated.
[0065] As a result, the number of patterns of the "blind decode"
performing PDCCH format in the mobile station UE#1 and the mobile
station UE#2 can further be decreased.
[0066] In the case where the time-division information is not
previously transmitted through the RRC signaling, in each subframe,
the mobile station UE#1 and the mobile station UE#2 may perform the
"blind decode" to the "DL resource allocation" transmitting PDCCH
format, the "UL grant" transmitting PDCCH format, the PDCCH format
notifying that the opportunity to perform the
transmission/reception (UE#1.fwdarw.UE#2) through the Ud interface
is allocated, and the PDCCH format notifying that the opportunity
to perform the transmission/reception (UE#2.fwdarw.UE#1) through
the Ud interface is allocated.
[0067] In such cases, the number of patterns of the "blind decode"
performing PDCCH format is increased in the mobile station UE#1 and
the mobile station UE#2. However, the subframe to which the
opportunity to perform the transmission/reception through the Uu
interface is allocated and the subframe to which the opportunity to
perform the transmission/reception through the Ud interface is
possibly allocated are not previously fixed, so that the radio base
station eNB can flexibly allocate the opportunity to perform the
transmission/reception through the Uu/Ud interface based on a data
signal amount and the like.
[0068] In the case 1, it is necessary for the mobile station UE#1
and the mobile station UE#2 to have an ability to perform not only
the transmission through the Uu/Ud interface but also the reception
through the Ud interface at the frequency F2. That is, the mobile
station UE#1 and the mobile station UE#2 need to support a TDD
(Time Divisional Duplexing) function at the frequency F2.
[0069] <Case 2>
[0070] Paints different from the operation in the case 1 will
mainly be described with reference to FIG. 4.
[0071] As illustrated in FIG. 4, in the case 2, the
transmission/reception through the Ud interface and the
transmission/reception of the downlink through the Uu interface are
configured to be performed in the time-division manner at the
frequency F1.
[0072] As illustrated in FIG. 4, in the case 2, the
transmission/reception of the uplink through the Uu interface is
configured to be performed at the frequency F2.
[0073] Specifically, the allocation unit 11 is configured to
perform the allocation similar to that of the conventional LTE
system to the opportunity to perform the transmission/reception of
the uplink through the Uu interface and the opportunity to perform
the transmission/reception of the downlink through the Uu
interface.
[0074] That is, the allocation unit 11 is configured to allocate
the PDSCH (that is, the "Uu DL") to the subframe identical to that
of the PDCCH, and to allocate the PUSCH (that is, the "Uu UL") to
the subframe that is located behind the subframe, to which the
PDCCH is allocated, by X subframes.
[0075] However, the allocation unit 11 is configured to allocate
the opportunity to perform the transmission/reception of the uplink
through the Uu interface to the subframe that is located behind the
subframe, to which the PDCCH is allocated, by X1 (X.ltoreq.X1)
subframes.
[0076] This is because the subframe (for example, subframes #2, #4,
#6, and #8) in which the PDCCH cannot be received in the mobile
station UE#1 and the mobile station UE#2 is generated with
insertion of the opportunity to perform the transmission/reception
through the Ud interface at the frequency F1.
[0077] Accordingly, the allocation unit 11 is configured to perform
the PUSCH allocation, which should be performed through the PDCCH
in the subframe (for example, subframes #2, #4, #6, and #8) in
which the PDCCH cannot be received, using the PDCCH in the subframe
(for example, subframes #1, #3, #5, and #7) located ahead by
one.
[0078] On the other hand, the allocation unit 11 is configured to
determine the opportunity to perform the transmission/reception
through the Ud interface in consideration of the processing delay
until the data signal (transport block) is generated in the mobile
station UE#1 and mobile station UE#2.
[0079] However, because the sub frame (for example, subframes #2,
#4, #6, and #8) in which the PDCCH cannot be received in the mobile
station UE#1 and the mobile station UE#2 is generated with the
insertion of the opportunity to perform the transmission/reception
through the Ud interface at the frequency F1, the allocation unit
11 may be configured to allocate the opportunity to perform the
transmission/reception of the uplink through the Ud interface to
the subframe that is located behind the subframe, to which the
PDCCH is allocated, by Y1 (Y.ltoreq.Y1) subframes.
[0080] Thus, in consideration of the generation of the subframe in
which the PDCCH cannot be received, the transmission unit 12 may be
configured to notify of the subframe in which the
transmission/reception of the data signal should be performed
through the Ud interface.
[0081] For example, the transmission unit 12 may be configured to
notify of information ("subframe index") indicating how many
subframes the allocation of the opportunity to perform the
transmission/reception through the Ud interface is located ahead of
the subframe, to which the PDCCH is allocated, using a "code point"
in a specific field of the PDCCH.
[0082] The transmission unit 12 may be configured to previously
notify of mapping of the "code point" and the "subframe index"
through the RRC signaling.
[0083] Alternatively, in the case where the mobile station UE#1 and
the mobile station UE#2 receive the PDCCH, the mobile station UE#1
and the mobile station UE#2 may be configured to initially set the
subframe in which the transmission/reception can be performed
through the Ud interface to the subframe in which the
transmission/reception of the data signal should be performed
through the Ud interface, after a time (X ms) corresponding to the
processing delay elapses.
[0084] In the case 2, it is necessary for the mobile station UE#1
and the mobile station UE#2 to nave the ability to perform not only
the transmission through the Ud interface but also the reception
through the Uu/Ud interface at the frequency F1. That is, the
mobile station UE#1 and the mobile station UE#2 need to support the
TDD function at the frequency F1.
[0085] The mobile station UE#1 and the mobile station UE#2 may be
configured to be able to receive the PDCCH even in the subframe in
which the mobile station UE#1 and the mobile station UE#2 should
perform the transmission/reception of the data signal through the
Ud interface.
[0086] In such cases, the transmission/reception of the data signal
through the Ud interface is performed for a remaining time except
reception timing (head 1 to 3 OFDM symbols of the subframe) of the
PDCCH. In this case, X1=X and Y1=Y are obtained.
[0087] <Case 3>
[0088] Points different from the operation in the cases 1 and 2
will mainly be described with reference to FIG. 5.
[0089] As illustrated in FIG. 5, in the case 3, the
transmission/reception of the downlink through the Ud interface is
configured to be performed at the frequency F1, the
transmission/reception of the uplink through the Uu interface is
configured to be performed at the frequency F2, and the
transmission/reception through the Ud interface is configured to be
performed at a frequency F3.
[0090] The transmission/reception (UE#1.fwdarw.UE#2) through the Ud
interface and the transmission/reception (UE#2.fwdarw.UE#1) through
the Ud interface are configured to be performed in the
time-division manner at the frequency F3.
[0091] In the case 3, the operation of the radio base station eNB
is similar to that of the case 1 except that the
transmission/reception through the Ud interface is performed at the
frequency F3.
[0092] In consideration of a plurality of frequencies (carriers)
for the transmission/reception through the Ud interface, the
allocation unit 11 may be configured to notify or information
("carrier index") indicating the frequency at which the
transmission/reception should be performed through she Ud interface
using the "code point" in the specific field of the PDCCH.
[0093] The transmission unit 12 may be configured to previously
notify of the mapping of the "code point" and the "carrier index"
through the RRC signaling.
[0094] The transmission unit 12 may be configured to previously
notify of the carrier mapped in each "carrier index" through the
RRC signaling.
[0095] In the case 3, it is necessary for the mobile station UE#1
and the mobile station UE#2 to have the ability to perform not only
the transmission through the Ud interface but also the reception
through the Ud interface at the frequency F3. That is, the mobile
station UE#1 and the mobile station UE#2 need to support the TDD
function at the frequency F3.
[0096] <Case 4>
[0097] Points different from the operation in the cases 1, 2, and 3
will mainly be described with reference to FIG. 6.
[0098] As illustrated in FIG. 6, in the case 4, the
transmission/reception of the downlink through the Uu interface is
configured to be performed at the frequency F1, the
transmission/reception of the uplink through the Uu interface is
configured to be performed at the frequency F2, the
transmission/reception (UE#1.fwdarw.UE#2) through the Ud interface
is configured to be performed at a frequency F3, and the
transmission/reception (UE#2.fwdarw.UE#1) through the Ud interface
is configured to be performed at a frequency F4.
[0099] That is, in the case 4, the multiplex of the
transmission/reception (UE#1.fwdarw.UE#2) through the Ud interface
and the transmission/reception (UE#2.fwdarw.UE#1) through the Ud
interface is FDD (Frequency Divisional Duplexing).
[0100] In the case 4, the operation of the radio base station eNB
is basically similar to that of the case 3. However, because the
transmission/reception (UE#1.fwdarw.UE#2) through the Ud interface
and the transmission/reception (UE#2.fwdarw.UE#1) through the Ud
interface are performed at different frequencies, the transmission
unit 12 needs not to transmit the "direction information".
[0101] In the case 4, it is necessary for the mobile station UE#1
to have the ability to perform the transmission through the Ud
interface at the frequency F3 while performing the reception
through the Ud interface at the frequency F4, and it is necessary
for the mobile station UE#2 to have the ability to perform the
transmission through the Ud interface at the frequency F4 while
performing the reception through the Ud interface at the frequency
F3.
[0102] However, desirably the frequency used in the
transmission/reception through the Ud interface is not restricted
by the combination of the mobile stations UE as much as possible,
but desirably the Ud interface can be set between the mobile
stations UE having the equal ability.
[0103] Accordingly, in the case 4, desirably the mobile station
UE#1 and the mobile station UE#2 have the ability to perform the
transmission/reception through the Ud interface at both the
frequencies F3 and F4.
[0104] From the viewpoint of the Radio frequency (RF) ability, this
is equivalent to the fact that the mobile station UE#1 and the
mobile station UE#2 support the transmission/reception through the
Ud interface at a plurality of frequencies (carriers) in the case
3.
[0105] In the case where the mobile station UE#1 and the mobile
station UE#2 support the transmission/reception through the Ud
interface at a plurality of frequencies (carriers), there are two
options, namely, the TDD and the FDD as a method for multiplexing
the transmission/reception (UE#1.fwdarw.UE#2) through the Ud
interface and the transmission/reception (UE#2.fwdarw.UE#1) through
the Ud interface.
[0106] For the TDD, the radio base station eNB provides the
"direction information" to the PDCCH format to enable the flexible
allocation according to a traffic amount in each of the
transmission/reception (UE#1.fwdarw.UE#2) through the Ud interface
and the transmission/reception (UE#2.fwdarw.UE#1) through the Ud
interface.
[0107] On the other hand, for the FDD, the necessity to provide the
"direction information" to the PDCCH format is eliminated.
[0108] In such cases, during the setting of the Ud interface,
frequency (carrier) used in the transmission/reception
(UE#1.fwdarw.UE#2) through the Ud interface or the
transmission/reception (UE#2.fwdarw.UE#1) through the Ud interface
is notified through the RRC signaling.
[0109] Accordingly, for example, which frequency (carrier) is used
in the transmission/reception (UE#1.fwdarw.UE#2) through the Ud
interface or the transmission/reception (UE#2.fwdarw.UE#1) through
the Ud interface is determined by the "carrier index" included in
the PDCCH.
[0110] For the TDD, in the case where the radio base station eNB
previously assigns the time-division of the transmission/reception
(UE#1.fwdarw.UE#2) through the Ud interface and the
transmission/reception (UE#2.fwdarw.UE#1) through the Ud interface
through the RRC signaling, the time-division can quasi-fixedly be
changed although the dynamic flexibility is degraded.
[0111] In such cases, it is not necessary for the radio base
station eNB to notify of the "direction information" in the PDCCH
format, and the number of patterns of the "blind decode" performing
PDCCH format can be decreased.
[0112] In all the cases above, the "direction information" is
notified in the PDCCH format, the mobile station UE#1 and the
mobile station UE#2 may previously be notified of a definition of
the information through the RRC signaling. That is, the mapping of
the "direction information" to the transmission/reception may
previously be notified through the RRC signaling.
[0113] For example, in the case where the "direction information"
is indicated by a one-bit information element on the PDCCH, the
mobile station UE#1 may be notified that the "direction
information=1" indicates the transmission while the "direction
information=0" is the reception, and the mobile station UE#2 may be
notified that the "direction information=0" indicates the
transmission while the "direction information=1" is the
reception.
[0114] In all the cases above, in the case where the mobile station
UE#1 and the mobile station UE#2 are notified of the "direction
information" through the RRC signaling while the "direction
information" on the PDCCH is eliminated, the PDCCH to which the
transmission/reception through the Ud interface is allocated may be
restricted so as to indicate the one-way allocation after the
"direction information" is set through the RRC signaling. In this
case, the RRC signaling is used again when the direction of the
transmission/reception is switched.
[0115] Alternatively, the "direction information" notified through
the RRC signaling may be configured to be tied to a periodic time
resource or frequency resource. In this case, the direction of the
transmission/reception is determined according to the time and
frequency resources allocated by the PDCCH.
[0116] The features of the embodiment may be expressed as
follows.
[0117] A first feature of the present invention is that a mobile
communication method for transmitting and receiving the data signal
and the control signal through the Uu interface (radio base station
interface) between the mobile station UE#1 (the first mobile
station) and the mobile station UE#2 (the second mobile station)
and the radio base station eNB, and for transmitting and receiving
the data signal through the Ud interface (the inter-mobile station
interface) between the mobile station UE#1 and the mobile station
UE#2, the mobile communication method includes: a step A in which
the radio base station eNB notifies the mobile station UE#1 and the
mobile station UE#2 that the opportunity to transmit and receive
the data signal through the Ud interface is allocated through the
PDCCH (the physical downlink control channel) in which the X-RNTI
(the common identification information) is used; and a step B in
which the radio base station eNB transmits the "direction
information (the transmission direction information)", for
notifying of the direction in which the data signal should be
transmitted in the opportunity, to the mobile station UE#1 and the
mobile station UE#2.
[0118] A second feature of the present invention is that a radio
base station eNB used in the mobile communication system configured
to be able to transmit and receive the data signal and the control
signal through the Uu interface between the mobile station UE#1 and
the mobile station UE#2 and the radio base station eNB, and to
transmit and receive the data signal through the Ud interface
between the mobile station UE#1 and the mobile station UE#2, the
radio base station eNB includes a transmission unit 12 configured
to notify the mobile station UE#1 and the mobile station UE#2 that
the opportunity to transmit and receive the data signal through the
Ud interface is allocated through the PDCCH in which the X-RNTI is
used, wherein the transmission unit 12 is configured to transmit
the "direction information", for notifying of the direction in
which the data signal should be transmitted in the opportunity, to
the mobile station UE#1 and the mobile station UE#2.
[0119] In the second feature of the present invention, the
transmission unit 12 may be configured to transmit the "direction
information" through the PDCCH in which the X-RNTI is used.
[0120] In the second feature of the present invention, the
transmission unit 12 may be configured to transmit the mapping of
the transmission and reception of the "direction information",
which is transmitted through the PDCCH, through the RRC
signaling.
[0121] In the second feature of the present invention, the
transmission unit 12 may be configured to transmit the "direction
information" through the RRC signaling.
[0122] In the second feature of the present invention, the
"direction information" may be tied to the periodic time resource
and frequency resource.
[0123] In the second feature of the present invention, the
transmission unit 12 may be configured to notify of the frequency,
at which the data signal should be transmitted and received through
the Ud interface, through the PDCCH in which the X-RNTI is
used.
[0124] In the second feature of the present invention, the
transmission unit 12 may be configured to notify of the frequency,
at which the data signal should be transmitted and received through
the Ud interface, through the RRC signaling.
[0125] In the second feature of the present invention, the
transmission unit 12 may be configured to notify of the subframe,
to which the data signal should be transmitted and received through
the Ud interface, through the PDCCH in which the X-RNTI is
used.
[0126] In the second feature of the present invention, the
transmission unit 12 may be configured to transmit and receive the
data signal and the control signal through the Uu interface through
the RRC signaling, and to transmit the time-division information
necessary to transmit and receive the data signal in the
time-division manner through the Ud interface through the RRC
signaling.
[0127] In the second feature of the present invention, the
transmission unit 12 may be configured such that the PDCCH format,
for notifying the opportunity to transmit and receive the data
signal through the Uu interface is allocated, is different from the
PDCCH format, for notifying the opportunity to transmit and receive
the data signal through the Ud interface is allocated.
[0128] The operations of the radio base station eNB and the mobile
stations UE#1 and UE#2 may be performed by hardware, a software
module executed by a processor, or a combination thereof.
[0129] The software module may be provided in any type of storage
medium such as a RAM (Random Access Memory), a flash memory, a ROM
(Read Only Memory), an EPROM (Erasable Programmable ROM), an EEPROM
(Electronically Erasable and Programmable ROM), a register, a hard
disk, a removable disk, and a CD-ROM.
[0130] The storage medium is connected to the processor such that
the processor can read and write the information in and from the
storage medium. The storage medium may be integrated in the
processor. The storage medium stay be provided in an ASIC. The ASIC
may be provided in the radio bass station eNB or the mobile
stations UE#1 and UE#2. The storage medium and the processor may be
provided as a discrete component in the radio base station eNB or
the mobile stations UE#1 and UE#.
[0131] Although the present invention is described above in detail
using the embodiment, it is clear for those skilled in the art that
the present invention is not limited to the embodiment. Various
modifications and changes can be made without departing from the
scope of the present invention. Accordingly, the description is
illustrative only, but not restrictive.
INDUSTRIAL APPLICABILITY
[0132] As described above, the present invention can provide the
mobile communication method and the radio base station, which can
properly adjust the transmission/reception timing of the data
signal and the control signal through the Uu interface and the
transmission/reception timing of the data signal through the Ud
interface.
REFERENCE SIGN LIST
[0133] UE#1,UE#2 mobile station
[0134] eNB radio base station
[0135] 11 allocation unit
[0136] 12 transmission unit
[0137] 13 reception unit
* * * * *