U.S. patent application number 13/593132 was filed with the patent office on 2012-12-13 for wireless transmitting apparatus, wireless receiving apparatus, wireless communication system, wireless transmitting method and wireless receiving method.
Invention is credited to Yasuhiro Hamaguchi, Yasuyuki Kato, Waho Oh, Hidekazu Tsuboi.
Application Number | 20120314805 13/593132 |
Document ID | / |
Family ID | 37899835 |
Filed Date | 2012-12-13 |
United States Patent
Application |
20120314805 |
Kind Code |
A1 |
Tsuboi; Hidekazu ; et
al. |
December 13, 2012 |
WIRELESS TRANSMITTING APPARATUS, WIRELESS RECEIVING APPARATUS,
WIRELESS COMMUNICATION SYSTEM, WIRELESS TRANSMITTING METHOD AND
WIRELESS RECEIVING METHOD
Abstract
To enable shared control information to be demodulated without
requiring advance information on a MIMO block or non-MIMO block
prior to demodulation of the shared control information of the
block, and further enable the shared control information to be
demodulated early. A wireless transmitting apparatus which performs
wireless transmission in MIMO or non-MIMO for each radio frame
comprised of a block or a plurality of blocks, and has mapping
sections (110-1 to 110-n) that perform mapping of pilot signals to
perform propagation path estimation, specific data, and user data,
where the mapping sections perform mapping so that the specific
data is transmitted in non-MIMO in the block or the radio frame
transmitted in MIMO, and that an antenna that transmits the
specific data is beforehand associated with an antenna that
transmits a pilot signal to perform propagation path
estimation.
Inventors: |
Tsuboi; Hidekazu;
(Chiba-shi, JP) ; Hamaguchi; Yasuhiro;
(Ichihara-shi, JP) ; Kato; Yasuyuki; (Chiba-shi,
JP) ; Oh; Waho; (Chiba-shi, JP) |
Family ID: |
37899835 |
Appl. No.: |
13/593132 |
Filed: |
August 23, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12088068 |
Mar 25, 2008 |
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PCT/JP2006/319553 |
Sep 29, 2006 |
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13593132 |
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Current U.S.
Class: |
375/295 |
Current CPC
Class: |
H04B 7/0413 20130101;
H04L 5/0007 20130101; H04L 5/0023 20130101; H04L 5/0048 20130101;
H04L 25/0226 20130101; H04B 7/0684 20130101 |
Class at
Publication: |
375/295 |
International
Class: |
H04L 27/00 20060101
H04L027/00 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 30, 2005 |
JP |
2005-289278 |
Jan 13, 2006 |
JP |
2006-006384 |
Claims
1. A wireless transmitting apparatus in a wireless communication
system, which is comprised of the wireless transmitting apparatus
that has a plurality of transmission antennas and a wireless
receiving apparatus that has a plurality of reception antennas, the
wireless transmitting apparatus comprising: a plurality of
transmission antennas, wherein at least one transmission antenna of
the plurality of transmission antennas is configured to transmit,
to the wireless receiving apparatus, MIMO data or non-MIMO data for
each block comprised of a plurality of sub-blocks; and a circuit
configured to perform: control to generate the non-MIMO data to
transmit the non-MIMO data to the wireless receiving apparatus
using only one transmission antenna of the plurality of
transmission antennas, and control to generate the non-MIMO data to
transmit the non-MIMO data to the wireless receiving apparatus
using all transmission antennas of the plurality of transmission
antennas.
2. The wireless transmitting apparatus according to claim 1,
wherein the circuit is further configured to perform control to
generate the MIMO data to transmit the MIMO data to the wireless
receiving apparatus using said all transmission antennas of the
plurality of transmission antennas.
3. The wireless transmitting apparatus according to claim 1,
wherein said control is performed in a certain slot.
4. The wireless transmitting apparatus according to claim 3,
wherein the circuit is further configured to perform, in a certain
slot, control to generate the MIMO data to transmit the MIMO data
to the wireless receiving apparatus using said all transmission
antennas of the plurality of transmission antennas.
5. A transmitting method of a wireless transmitting apparatus in a
wireless communication system, which is comprised of the wireless
transmitting apparatus that has a plurality of transmission
antennas and a wireless receiving apparatus that has a plurality of
reception antennas, the transmitting method comprising:
transmitting, MIMO data or non-MIMO data, to the wireless receiving
apparatus, for each block comprised of a plurality of sub-blocks by
using at least one transmission antenna of the plurality of
transmission antennas; controlling generation of the non-MIMO data
to transmit the non-MIMO data to the wireless receiving apparatus
using only one transmission antenna of the plurality of
transmission antennas; and controlling generation of the non-MIMO
data to transmit the non-MIMO data to the wireless receiving
apparatus using all transmission antennas of the plurality of
transmission antennas.
6. The transmitting method according to claim 5, further
comprising: controlling generation of the MIMO data to transmit the
MIMO data to the wireless receiving apparatus using said all
transmission antennas of the plurality of transmission
antennas.
7. The transmitting method according to claim 5, wherein said
control is performed in a certain slot.
8. The transmitting method according to claim 7, further
comprising: controlling, in a certain slot, generation of the MIMO
data to transmit the MIMO data to the wireless receiving apparatus
using said all transmission antennas of the plurality of
transmission antennas.
9. A circuit causing a wireless transmitting apparatus to exhibit a
function by being mounted in the wireless transmitting apparatus in
a wireless communication system, which is comprised of the wireless
transmitting apparatus that has a plurality of transmission
antennas and a wireless receiving apparatus that has a plurality of
reception antennas, the circuit causing the wireless transmitting
apparatus to exhibit the function of performing: transmitting, MIMO
data or non-MIMO data, to the wireless receiving apparatus, for
each block comprised of a plurality of sub-blocks by using at least
one transmission antenna of the plurality of transmission antennas;
controlling generation of the non-MIMO data to transmit the
non-MIMO data to the wireless receiving apparatus using only one
transmission antenna of the plurality of transmission antennas; and
controlling generation of the non-MIMO data to transmit the
non-MIMO data to the wireless receiving apparatus using all
transmission antennas of the plurality of transmission
antennas.
10. The circuit according to claim 9, further causing the wireless
transmitting apparatus to exhibit a function of performing:
controlling generation of the MIMO data to transmit the MIMO data
to the wireless receiving apparatus using said all transmission
antennas of the plurality of transmission antennas.
11. The circuit according to claim 9, wherein said control is
performed in a certain slot.
12. The circuit according to claim 11, further causing the wireless
transmitting apparatus to exhibit a function of performing:
controlling, in a certain slot, generation of the MIMO data to
transmit the MIMO data to the wireless receiving apparatus using
said all transmission antennas of the plurality of transmission
antennas.
13. A non-transitory computer-readable medium having instructions
stored thereon, such that when the instructions are read and
executed by a processor, the processor is configured to perform
said transmitting method according to claim 5.
14. A wireless transmitting apparatus comprising: a non-transitory
computer-readable medium having instructions stored thereon, such
that when the instructions are read and executed by a processor,
the processor is configured to perform said transmitting method
according to claim 5.
15. The wireless transmitting apparatus according to claim 1,
further comprising: a non-transitory computer-readable medium
having instructions stored thereon, such that when the instructions
are read and executed by a processor, the processor is configured
to function as the means of the wireless transmitting apparatus
according to claim 1.
Description
[0001] This application is a Divisional of co-pending application
Ser. No. 12/088,068 filed on Mar. 25, 2008 and for which priority
is claimed under 35 U.S.C. .sctn.120. Application Ser. No.
12/088,068 is the national phase of PCT International Application
No. PCT/JP2006/319553 filed on Sep. 29, 2006 under 35 U.S.C.
.sctn.371, which claims the benefit of priority of Japanese Patent
Application No. 2006-006384, filed on Jan. 13, 2006, and Japanese
Patent Application No. 2005-289278, filed on Sep. 30, 2005. The
entire contents of each of the above-identified applications are
hereby incorporated by reference.
TECHNICAL FIELD
[0002] The present invention relates to a wireless transmitting
apparatus, wireless receiving apparatus, wireless communication
system, wireless transmitting method and wireless receiving method
for performing estimation of a propagation path of a radio zone,
and demodulating a signal using the propagation path estimation
result.
BACKGROUND ART
[0003] Conventionally, in 3GPP (3rd Generation Partnership
Project), the W-CDMA system has been standardized as a
3rd-generation cellular mobile communication system, and the
service of the system has been started sequentially. Further, HSDPA
(High-Speed Downlink Packet Access) with the communication speed
further increased has been standardized, and its service has been
about to start.
[0004] Meanwhile, evolution of 3rd-generation radio access (Evolved
Universal Terrestrial Radio Access: hereinafter referred to as
EUTRA) has been studied in 3GPP. The OFDM (Orthogonal Frequency
Division Multiplexing) system is proposed for downlink in EUTRA.
OFDM is a scheme which is used in IEEE802.11a that is a wireless
system of 5 GHz-band and digital terrestrial broadcasting, and
which provides simultaneous communications with tens to thousands
of carriers allocated in minimum frequency-intervals that do not
cause interference in theory. Generally, the carrier is referred to
as a subcarrier in OFDM. Then, digital modulation such as PSK, QAM
or the like is performed on each subcarrier to perform
communications.
[0005] FIG. 15 is a diagram showing a configuration example of a
downlink radio frame assumed based on the proposal of 3GPP in EUTRA
(see Non-patent Documents 1 to 3). As shown in FIG. 15, the
downlink radio frame is comprised of a plurality of blocks each of
which is a unit radio resource used in communications. There is the
case that block is referred to as Chunk.
[0006] Further, the block is comprised of a plurality of
sub-blocks, with the sub-block as a minimum unit being defined by a
sub-channel as a frequency component corresponding to a single or
plurality of subcarriers and a sub-slot as a time component
corresponding to a single or plurality of OFDM symbols.
[0007] The slot is expressed in two dimensions of a block bandwidth
on the frequency axis and a slot on the time axis. There is the
case that this slot is referred to as TTI (Transmission Time
Interval). For example, when it is assumed that the entire downlink
band (downlink frequency bandwidth) Ball is 20 MHz, a block
bandwidth Bch is 300 kHz, a subcarrier frequency bandwidth Bsc is
15 kHz, a single radio frame length is 10 ms, and that TTI is 0.5
ms, a single radio frame is comprised of sixty blocks on the
frequency axis and twenty blocks on the time axis, i.e. 1200
blocks.
[0008] Further, one block contains twenty subcarriers, and when the
OFDM symbol duration Ts is assumed to be 0.0625 ms, it is
calculated that one block contains eight OFDM symbols. Accordingly,
as shown in FIG. 16, one block can be expressed by configuration
C(f,t) when the number of sub-channels is f and the number of
sub-slots is t (in the above-mentioned example, when it is assumed
that one sub-channel is one subcarrier, and that one sub-slot is
one OFDM symbol, equations of 1.ltoreq.f.ltoreq.20 and
1.ltoreq.t.ltoreq.8 hold.)
[0009] In the block are mapped:
(1) user data for use by a user; (2) physical and layer 2 control
messages (hereinafter, referred to as "shared control information")
included in Downlink Shared Control Signaling Channel (DSCSCH)
storing a mobile station ID (UE identity), modulation scheme, error
correcting scheme, information required for the processing of
Hybrid Automatic Repeat reQuest (HARQ), and transmission parameters
such as a data length and the like; and (3) a known pilot signal
used in propagation path estimation to demodulate control data and
user data.
[0010] Further, at the beginning of the radio frame are mapped (1)
a synchronization signal to acquire synchronization of the frame
and (2) common control information to broadcast the structure of
the entire frame.
[0011] The shared control information is described in Non-patent
Document 2. In other words, Non-patent Document 2 defines as
channels in the physical layer:
(1) Pilot channel (Pilot signal); (2) Common control channel
(common control information); (3) Shared control signaling channel
(shared control information); (4) Shared data channel (user data);
(5) Multicast/Broadcast channel; and (6) Downlink synchronization
channel (synchronization signal.
[0012] A block (chunk) to transmit data to a terminal (user, mobile
station) is basically comprised of a pilot channel (pilot signal),
shared control signaling channel (shared control information) and
shared data channel (user data).
[0013] The pilot channel (pilot signal) is used in power
measurement in performing a cell search and handover, CQI
measurement to perform adaptive modulation, and channel estimation
to demodulate the shared control information and user data.
[0014] The shared control signaling channel (shared control
information) includes control information required for demodulation
of user data, such as a modulation scheme of the block (chunk),
data length, position of data to the terminal in the block (chunk),
Hybrid ARQ information, and the like, and further as control
information for uplink from the terminal, information of power
control, transmission timing control, timing at which the terminal
has to transmit, modulation scheme, data length, ACK/NACK to the
data transmitted from the terminal, and the like.
[0015] The shared data channel (user data) is user data of the
above-mentioned block (chunk), and sometimes shared by a plurality
of users.
[0016] To demodulate the user data, the information of the
modulation scheme, data length and the like in the shared control
information is indispensable, and to demodulate the shared control
information, propagation path compensation is made using the pilot
signal.
[0017] FIG. 17A is a diagram of a block extracted from FIG. 15, and
FIG. 17B is a diagram of another extracted block of a structure
with part of pilot signals arranged in the center of TTI as another
configuration example that is similarly proposed. In both of FIGS.
17A and 17B, by allocating the shared control information to
demodulate the user data at the beginning of the block, it is
intended to ease demodulation of user data in the terminal. In
other words, since the need is eliminated for processing of storing
user data in a buffer until all the shared control information in
the block is obtained and the like, it is possible to reduce the
circuit scale, and further reduce the demodulation processing
delay.
[0018] Moreover, the shared control information is data important
to demodulate the user data, a noise-immunity fixed modulation
scheme such as QPSK or the like is used for the information to
prevent the occurrence of demodulation error, and the information
is disposed near the pilot signal to enhance propagation path
estimation accuracy.
[0019] Further, in EUTRA, the MIMO (Multi-Input Multi-Output)
technique is used which is a technique of transmitting different
signals from a plurality of transmission antennas, and receiving
the signals with a plurality of reception antennas to separate the
received signals. FIG. 18 is a concept diagram of a communication
system using the MIMO technique. In the MIMO technique, a
transmitter 100 has a plurality of (M) transmission antennas 101-1
to 101-M, a receiver 102 has a plurality of (N) reception antennas
103-1 to 103-N, and MIMO propagation paths are formed using the
transmission antennas 101-1 to 101-M and reception antennas 103-1
to 103-N. Then, a plurality of different data signals is
transmitted and received via a plurality of propagation paths by
radio signals with the same frequency or in overlapping frequency
bands.
[0020] Herein, it is assumed in FIG. 18 that a propagation path
from the antenna 101-1 to antenna 103-1 is h.sub.11, a propagation
path from the antenna 101-2 to antenna 103-1 is h.sub.21, a
propagation path from the antenna 101-M to antenna 103-1 is
h.sub.M1, and that, a propagation path from the antenna 101-M to
antenna 103-N is h.sub.MN. When it is further assumed that a
transmission signal from the antenna 101-1 is S.sub.1, a
transmission signal from the antenna 101-2 is S.sub.2, a
transmission signal from the antenna 101-M is S.sub.M, a received
signal in the antenna 103-1 is R.sub.1, a received signal in the
antenna 103-2 is R.sub.2, and that a received signal in the antenna
103-N is R.sub.N, following equation (1) holds.
[ Eq . 1 ] ( R 1 R 2 R N ) = ( h 11 h 21 h M 1 h 12 h 22 h M 2 h 1
N h 2 N h MN ) ( S 1 S 2 S M ) ( 1 ) ##EQU00001##
[0021] To obtain each h with ease, for example, when it is assumed
that M=2 and N=2, it is considered that sub-slots including pilot
signals as shown in FIG. 17A are configured as shown in FIG. 19. In
other words, it is controlled that on the sub-channel to transmit
the pilot signal from the first transmission antenna, a signal is
not transmitted from the second antenna. In the receiver, using
only the pilot signals transmitted from the first transmission
antenna among received pilot signals, it is possible to estimate
propagation paths h.sub.11 and h.sub.12 by performing linear
interpolation, averaging and the like among the pilots. Similarly,
using only the pilot signals transmitted from the second
transmission antenna among received pilot signals, it is possible
to estimate propagation paths h.sub.21 and h.sub.22.
[0022] Next, the receiver generates candidates S'.sub.1 and
S'.sub.2 for the transmission signal, and obtains R'.sub.1 and
R'.sub.2 from equation (2) as described below.
[ Eq . 2 ] ( R 1 ' R 2 ' ) = ( h 11 h 21 h 12 h 22 ) ( S 1 ' S 2 '
) ( 2 ) ##EQU00002##
[0023] Then, a difference is obtained between R' obtained in the
above-mentioned equation and received signal R, and S' that
minimizes the difference is output as a signal S to be desired.
This method is called MLC (Maximum Likelihood Detection), and
further, another reception method is considered such as QRM-MLD as
shown in Non-patent Document 4 although descriptions thereof are
omitted herein.
[0024] When configurations in one block for each antenna in using
the MIMO technique are defined as C1(f, t), C2(f, t), . . . ,
CM(f,t), pilot signals are required for each antenna to use the
MIMO technique. For example, when the number of transmission
antennas is two (M=2), such a block structure has been proposed
that as shown in FIG. 20, in a position in the configuration where
a pilot signal is transmitted from the first antenna, a pilot
signal is not transmitted from the other transmission antenna
(second transmission antenna) (null is disposed), thereby enabling
the receiver to receive the independent pilot signal for each
antenna, and that the other shared control information and user
data is transmitted concurrently from each antenna.
[0025] As described above, the MIMO technique is a technique
applicable on a block basis, and it is possible to provide both a
MIMO block and non-MIMO block in a frame of EUTRA.
[0026] Using the frame structure as described above, described next
is transmission and reception assumed based on the proposal of 3GPP
with reference to drawings. FIG. 21 is a block diagram showing a
schematic configuration of a conventional transmitter, and FIGS. 22
and 23 are block diagrams showing schematic configurations of
conventional receivers. In addition, in the following description,
it is assumed that a single block in a single radio frame is
assigned to a single user. However, without being limited thereto,
one user may use a plurality of blocks, or one block may be shared
by a plurality of users.
[0027] As shown in FIG. 21, for example, in the transmitter in a
base station, transmission data (shared control information and
user data) for each user subjected to modulation processing is
input to mapping circuits 120-1 to 120-n of each block together
with a pilot signal. Each of the mapping circuits 120-1 to 120-n is
comprised of a selector 120a, splitter 120b, and memories 120c-1 to
120c-M, and to provide the block structure as shown in FIG. 17A,
the transmission data of each user and the pilot signal is arranged
on the memories (configuration of FIG. 16) via the selector 120a
and splitter 120b. Herein, in the block using the MIMO technique,
the pilot signal is allocated to the memory of each antenna from
the selector 120a, and the shared control information and user data
is output to the memory of each antenna from the splitter 120b. In
the block without using the MIMO technique, the same pilot signal
and transmission data is allocated for all the antennas.
[0028] Signals allocated onto the memories in each of the mapping
circuits 120-1 to 120-n are sequentially output to F/T transform
circuits 121-1 to 121-M for each antenna, starting with the
beginning of the frame, and signals of the entire band are
transformed by IFFT (Inverse Fast Fourier Transform) computation
from signals in the frequency domain to signals in the time domain.
The transformed signals are converted into analog signals in D/A
conversion circuits 122-1 to 122-M, further converted into signals
with frequencies to transmit in the frequency conversion circuits
123-1 to 123-M, and then, transmitted from a first transmission
antenna 124-1 to Mth transmission antenna 124-M.
[0029] The terminal is beforehand notified of whether a block to
the terminal is transmitted as a MIMO signal or a non-MIMO signal
by advance information such as the common control information or
the like. Based on the notified advance information, when the block
to the terminal is a non-MIMO signal, the terminal demodulates the
data by the following processing using the receiver as shown in
FIG. 22. In other words, as shown in FIG. 22, the signal received
in an antenna 130 is converted into a signal with an intermediate
frequency in a frequency conversion circuit 131. The analog signal
converted into the intermediate frequency is converted into a
digital signal in an A/D conversion circuit 132, and output to a
T/F transform circuit 133.
[0030] The signal input to the T/F transform circuit 133 is
subjected to FFT (Fast Fourier Transform) computation, and the
signal in the time domain is thereby transformed into the signal in
the frequency domain. A propagation path estimating circuit 134
calculates a propagation path estimation value for each sub-channel
from the change in phaseamplitude of the pilot signal that is a
known signal, and outputs the value to a propagation path
compensating circuit 135. Using the estimation value calculated in
the propagation path estimating circuit 134, the propagation path
compensating circuit 135 compensates the received signal
transformed in the T/F transform circuit 133 to be a transmission
signal prior to being changed by the propagation path. A data
demodulation circuit 136 demodulates the data signal compensated in
the propagation path compensating circuit 135.
[0031] Herein, as the method of calculating an estimation value in
the propagation path estimating circuit 134, for example, methods
as shown in FIG. 24A and FIG. 24B and the like can be adopted. The
method as shown in FIG. 24A is to obtain an average of changes in
phaseamplitude of a plurality of pilot signals, and use the
obtained average value as the change in phaseamplitude of a
sub-channel positioned between the pilot signals. The method as
shown in FIG. 24B is to make linear interpolation of changes in
phaseamplitude of a plurality of pilot signals, and use the
obtained interpolation value as the change in phaseamplitude of a
sub-channel positioned between the pilot signals.
[0032] Meanwhile, when the block to the terminal is a MIMO signal,
the terminal demodulates the data by the following processing using
the receiver of FIG. 23. In other words, as shown in FIG. 23,
received signals received in a first reception antenna 140-1 to Nth
reception antenna 140-N are converted into signals with the
intermediate frequency in frequency conversion circuits 141-1 to
141-N, and then, converted into digital signals in A/D conversion
circuits 142-1 to 142-N. The digital signals in the time domain
converted in the A/D conversion circuits 142-1 to 142-N are
transformed into signals in the frequency domain by FFT computation
in T/F transform circuits 143-1 to 143-N, and output to an MLD
(Maximum-Likelihood Detection) circuit 144. The MLD circuit 144 has
a propagation path estimating circuit 145, metric circuit 146, and
comparing circuit 147, performs propagation path estimation and
demodulation processing of the data, and outputs reception data.
[0033] Non-patent Document 1: R1-050705 "Pilot Channel Structure in
Evolved UTRA Downlink" 3GPP TSG RAN WG1 #42 on LTE London, UK, Aug.
29-Sep. 2, 2005 [0034] Non-patent Document 2: R1-050707 "Physical
Channels and Multiplexing in Evolved UTRA Downlink" 3GPP TSG RAN
WG1 #42 on LTE London, UK, Aug. 29-Sep. 2, 2005 [0035] Non-patent
Document 3: R1-050852 "CQI-based Transmission Power Control for
Control Channel in Evolved UTRA" 3GPP TSG RAN WG1 #42 on LTE
London, UK, Aug. 29-Sep. 2, 2005 [0036] Non-patent Document 4:
"MIMO (Multi Input Multi Output) Related Technique" Website of
Japan Patent Office:
http//www.jpo.go.jp/shiryou/s_sonota/hyoujun/gijutsu/mimo/mokuji.htm
DISCLOSURE OF INVENTION
Problems to be Solved by the Invention
[0037] However, in the conventional technique, generally, since
different demodulation methods are used in a MIMO block and
non-MIMO block, it is necessary to beforehand notify whether a
block is transmitted as a MIMO signal or non-MIMO signal by advance
information such as common control information or the like.
Further, in the MIMO block, it is not possible to perform
demodulation processing of the shared control information until
pilot signals are received from all transmission antennas.
[0038] The present invention is carried out in view of such
circumstances, and it is an object of the invention to provide a
wireless transmitting apparatus, wireless receiving apparatus,
wireless communication system, wireless transmitting method and
wireless receiving method enabling shared control information to be
demodulated without requiring advance information on a MIMO block
or non-MIMO block prior to demodulation of the shared control
information of the block, and further enabling the shared control
information to be demodulated early.
Means for Solving the Problem
[0039] (1) To achieve the aforementioned object, the present
invention takes following means. In other words, a wireless
communication apparatus according to the invention is a wireless
transmitting apparatus that has a plurality of antennas and that
performs wireless transmission in MIMO or non-MIMO on a radio frame
basis using an OFDM signal, where the radio frame is comprised of a
block or a plurality of blocks each comprised of a plurality of
sub-blocks with a sub-block as a minimum unit being defined by a
sub-channel as a frequency component corresponding to a single or a
plurality of subcarriers and a sub-slot as a time component
corresponding to a single or a plurality of OFDM symbols, and is
characterized by having a mapping section that performs mapping of
a pilot signal to perform propagation path estimation, specific
data, and user data, where the mapping section performs mapping so
that the specific data is transmitted in non-MIMO in the block or
the radio frame transmitted in MIMO, and that an antenna that
transmits the specific data is beforehand associated with an
antenna that transmits the pilot signal to perform propagation path
estimation.
[0040] Thus, since mapping is performed so that the specific data
is transmitted in non-MIMO in the block or the radio frame
transmitted in MIMO, and that an antenna that transmits the
specific data is beforehand associated with an antenna that
transmits the pilot signal to perform propagation path estimation,
the receiving side is capable of grasping the content of the
specific data in the stage of receiving the sub-block including the
specific data. Particularly, when the specific data is mapped into
the beginning of the block, the receiving side is capable of
grasping the content indicated by the specific data only by
receiving one sub-block of the beginning. Accordingly, for example,
when the specific data includes information of a destination, it is
possible to grasp whether or not the block is to the terminal in
the stage of receiving the sub-block of the beginning, and it is
thus possible to early determine whether or not to demodulate a
subsequently arriving sub-block or block. As a result, power
reduction can be made on the receiving side. Further, when the
specific data mapped into the beginning of the block includes
information indicating whether transmission is in MIMO or non-MIMO,
the receiving side is capable of determining MIMO or non-MIMO in
the stage of receiving the specific data, and therefore, the need
is eliminated for notifying advance information to notify whether
transmission is in MIMO or non-MIMO.
[0041] (2) Further, in the wireless transmitting apparatus
according to the invention, the mapping section is characterized by
performing mapping in the block or the radio frame to perform
wireless transmission in MIMO so that an antenna that transmits the
specific data is the same as an antenna that transmits a pilot
signal with a frequency component nearest the specific data in the
same sub-slot.
[0042] Thus, mapping is performed so that an antenna that transmits
the specific data is the same as an antenna that transmits a pilot
signal with a frequency component nearest the specific data in the
same sub-slot, and it is thus possible to enhance accuracy in
propagation path estimation on the receiving side. Further, since
the specific data mapped in the block to perform wireless
transmission in MIMO is transmitted as a radio signal in non-MIMO,
the receiving side is capable of demodulating the specific data in
either MIMO or non-MIMO. Accordingly, for example, when the
specific data includes information of a destination, it is possible
to grasp whether or not the block is to the terminal in the stage
of receiving the sub-block of the beginning, and it is thus
possible to early determine whether or not to demodulate a
subsequently arriving sub-block or block. As a result, power
reduction can be made on the receiving side. Further, when the
specific data mapped into the beginning of the block includes
information indicating whether transmission is in MIMO or non-MIMO,
the receiving side is capable of determining MIMO or non-MIMO in
the stage of receiving the specific data, and therefore, the need
is eliminated for notifying advance information to notify whether
transmission is in MIMO or non-MIMO. Furthermore, the invention
adopts such a configuration, and therefore, is capable of being
carried into practice without making a modification to the block
(Chunk) structure currently proposed by 3GPP.
[0043] (3) Further, in the wireless transmitting apparatus
according to the invention, the mapping section is characterized by
performing mapping in the block or the radio frame to perform
wireless transmission in MIMO so that an antenna that transmits the
specific data is the same as an antenna that transmits a pilot
signal nearest the specific data on the low frequency side or the
high frequency side in the same sub-slot.
[0044] Thus, mapping is performed so that an antenna that transmits
the specific data is the same as an antenna that transmits a pilot
signal nearest the specific data on the low frequency side or the
high frequency side in the same sub-slot, and it is thus possible
to enhance accuracy in propagation path estimation on the receiving
side, while the need is eliminated for calculating the distance
between the nearest pilot signal and the specific data. Further,
since the specific data mapped in the block to perform wireless
transmission in MIMO is transmitted as a radio signal in non-MIMO,
the receiving side is capable of demodulating the specific data in
either MIMO or non-MIMO. Accordingly, for example, when the
specific data includes information of a destination, it is possible
to grasp whether or not the block is to the terminal in the stage
of receiving the sub-block of the beginning, and it is thus
possible to early determine whether or not to demodulate a
subsequently arriving sub-block or block. As a result, power
reduction can be made on the receiving side. Further, when the
specific data mapped into the beginning of the block includes
information indicating whether transmission is in MIMO or non-MIMO,
the receiving side is capable of determining MIMO or non-MIMO in
the stage of receiving the specific data, and therefore, the need
is eliminated for notifying advance information to notify whether
transmission is in MIMO or non-MIMO. Furthermore, the invention
adopts such a configuration, and therefore, is capable of being
carried into practice without making a modification to the block
(Chunk) structure currently proposed by 3GPP.
[0045] (4) Further, in the wireless transmitting apparatus
according to the invention, the mapping section is characterized by
performing mapping in the block or the radio frame to perform
wireless transmission in MIMO so that an antenna that transmits the
specific data is a predetermined single or plurality of
antennas.
[0046] Thus, mapping is performed in the block or the radio frame
to perform wireless transmission in MIMO so that an antenna that
transmits the specific data is a predetermined single or plurality
of antennas, and it is thus possible to simplify the mapping
operation and the demodulation operation on the receiving side.
Further, since the specific data mapped in the block to perform
wireless transmission in MIMO is transmitted as a radio signal in
non-MIMO, the receiving side is capable of demodulating the
specific data in either MIMO or non-MIMO. Accordingly, for example,
when the specific data includes information of a destination, it is
possible to grasp whether or not the block is to the terminal in
the stage of receiving the sub-block of the beginning, and it is
thus possible to early determine whether or not to demodulate a
subsequently arriving sub-block or block. As a result, power
reduction can be made on the receiving side. Further, when the
specific data mapped into the beginning of the block includes
information indicating whether transmission is in MIMO or non-MIMO,
the receiving side is capable of determining MIMO or non-MIMO in
the stage of receiving the specific data, and therefore, the need
is eliminated for notifying advance information to notify whether
transmission is in MIMO or non-MIMO. Furthermore, the invention
adopts such a configuration, and therefore, is capable of being
carried into practice without making a modification to the block
(Chunk) structure currently proposed by 3GPP.
[0047] (5) Further, in the wireless transmitting apparatus
according to the invention, it is a feature that the predetermined
antenna is selected based on reception quality information of each
transmission antenna acquired from the communicating party.
[0048] Thus, since the antenna is selected based on reception
quality information of each transmission antenna acquired from the
communicating party, it is possible to transmit a signal while
gathering power into only a transmission antenna providing good
reception quality, and as a result, demodulation error can be
reduced on the receiving side. Further, since the specific data
mapped in the block to perform wireless transmission in MIMO is
transmitted as a radio signal in non-MIMO, the receiving side is
capable of demodulating the specific data in either MIMO or
non-MIMO. Accordingly, for example, when the specific data includes
information of a destination, it is possible to grasp whether or
not the block is to the terminal in the stage of receiving the
sub-block of the beginning, and it is thus possible to early
determine whether or not to demodulate a subsequently arriving
sub-block or block. As a result, power reduction can be made on the
receiving side. Further, when the specific data mapped into the
beginning of the block includes information indicating whether
transmission is in MIMO or non-MIMO, the receiving side is capable
of determining MIMO or non-MIMO in the stage of receiving the
specific data, and therefore, the need is eliminated for notifying
advance information to notify whether transmission is in MIMO or
non-MIMO. Furthermore, the invention adopts such a configuration,
and therefore, is capable of being carried into practice without
making a modification to the block (Chunk) structure currently
proposed by 3GPP.
[0049] (6) Further, in the wireless transmitting apparatus
according to the invention, the mapping section is characterized by
performing mapping in the block to perform wireless transmission in
MIMO so that an antenna that transmits the specific data is all the
antennas that transmit pilot signals allocated in the sub-slot
including the specific data.
[0050] Thus, since mapping in the block to perform wireless
transmission in MIMO is performed so that an antenna that transmits
the specific data is all the antennas that transmit pilot signals
allocated in the sub-slot including the specific data, the
receiving side is capable of obtaining the change in phaseamplitude
of each antenna using pilot signals for each antenna in the MIMO
block, and by combining the values, compensating the propagation
path of the specific data with high accuracy. Further, since the
specific data mapped in the block to perform wireless transmission
in MIMO is transmitted as a radio signal in non-MIMO, the receiving
side is capable of demodulating the specific data in either MIMO or
non-MIMO. Accordingly, for example, when the specific data includes
information of a destination, it is possible to grasp whether or
not the block is to the terminal in the stage of receiving the
sub-block of the beginning, and it is thus possible to early
determine whether or not to demodulate a subsequently arriving
sub-block or block. As a result, power reduction can be made on the
receiving side. Further, when the specific data mapped into the
beginning of the block includes information indicating whether
transmission is in MIMO or non-MIMO, the receiving side is capable
of determining MIMO or non-MIMO in the stage of receiving the
specific data, and therefore, the need is eliminated for notifying
advance information to notify whether transmission is in MIMO or
non-MIMO. Furthermore, the invention adopts such a configuration,
and therefore, is capable of being carried into practice without
making a modification to the block (Chunk) structure currently
proposed by 3GPP.
[0051] (7) Further, in the wireless transmitting apparatus
according to the invention, it is another feature that the specific
data is a control signal including at least a destination of the
user data, and information on whether or not the block is a MIMO
block.
[0052] Thus, since the specific data is a control signal including
at least a destination of the user data, and information on whether
or not the block is a MIMO block, when the specific data is mapped
into the beginning of the block, the receiving side is capable of
grasping the content indicated by the specific data only by
receiving one sub-block of the beginning. In other words, it is
possible to grasp whether or not the block is to the terminal in
the stage of receiving the sub-block of the beginning, and it is
thus possible to early determine whether or not to demodulate a
subsequently arriving sub-block or block. As a result, power
reduction can be made on the receiving side. Further, the receiving
side is capable of determining MIMO or non-MIMO in the stage of
receiving the specific data, and therefore, the need is eliminated
for notifying advance information to notify whether transmission is
in MIMO or non-MIMO.
[0053] (8) Further, in the wireless transmitting apparatus
according to the invention, it is another feature that the specific
data is comprised of a plurality of same portions, and that the
plurality of same portions is transmitted from respective different
antennas when transmission is performed using a plurality of
antennas.
[0054] Thus, since the specific data is comprised of a plurality of
same portions, symbol repetitions are made, and the gain can be
increased. Further, when transmission is performed using a
plurality of antennas, a plurality of same portions is transmitted
from respective different antennas, and it is thereby possible to
obtain more sophisticated diversity effect.
[0055] (9) Further, a wireless receiving apparatus according to the
invention is a wireless receiving apparatus that receives an OFDM
signal wirelessly transmitted from the wireless transmitting
apparatus as described in claim 1, and is characterized by having a
propagation path estimating section that performs propagation path
estimation using a received pilot signal, and a propagation path
compensating section that compensates the specific data and the
user data for the propagation path from an estimation value
calculated in the propagation path estimating section, where the
propagation path compensating section uses a propagation path
estimation value calculated using a beforehand associated pilot
signal in compensating the specific data for the propagation
path.
[0056] Thus, a propagation path estimation value calculated using a
beforehand associated pilot signal is used in compensating the
specific data for the propagation path, and it is thereby possible
to enhance accuracy in propagation path estimation. Further, by
performing estimation of the propagation path while assuming that a
radio signal received in the reception antenna is a radio signal
transmitted in non-MIMO, when the specific data mapped in the block
to perform wireless transmission in MIMO in the communicating party
(transmitting side) is transmitted as a radio signal non-MIMO, it
is possible to demodulate the specific data either in MIMO or
non-MIMO. As a result, without making a modification to the block
(Chunk) structure currently proposed by 3GPP, it is possible to
construct a system that does not require the advance information to
notify whether transmission is in MIMO or non-MIMO.
[0057] (10) Further, in the wireless receiving apparatus according
to the invention, the propagation path estimating section is
characterized by using a propagation path estimation value
calculated using a pilot signal received in a frequency nearest the
frequency in which the specific data is received in the same
sub-slot, in compensating the specific data for the propagation
path.
[0058] Thus, a propagation path estimation value calculated using a
pilot signal received in a frequency nearest the frequency in which
the specific data is received in the same sub-slot is used in
compensating the specific data for the propagation path, and it is
thus possible to enhance accuracy in propagation path estimation,
while eliminating the need for calculating the distance between the
nearest pilot signal and the specific data. Further, by performing
estimation of the propagation path while assuming that a radio
signal received in the reception antenna is a radio signal
transmitted in non-MIMO, when the specific data mapped in the block
to perform wireless transmission in MIMO in the communicating party
(transmitting side) is transmitted as a radio signal in non-MIMO,
it is possible to demodulate the specific data either in MIMO or
non-MIMO. As a result, without making a modification to the block
(Chunk) structure currently proposed by 3GPP, it is possible to
construct a system that does not require the advance information to
notify whether transmission is in MIMO or non-MIMO.
[0059] (11) Further, in the wireless receiving apparatus according
to the invention, the propagation path estimating section is
characterized by using a propagation path estimation value
calculated using a pilot signal received in a frequency lower than
and nearest the frequency in which the specific data is received in
the same sub-slot or in a frequency higher than and nearest the
frequency in which the specific data is received, in compensating
the specific data for the propagation path.
[0060] Thus, a propagation path estimation value calculated using a
pilot signal received in a frequency lower than and nearest the
frequency in which the specific data is received in the same
sub-slot or in a frequency higher than and nearest the frequency in
which the specific data is received is used in compensating the
specific data for the propagation path, and it is thus possible to
enhance accuracy in propagation path estimation. Further, by
performing estimation of the propagation path while assuming that a
radio signal received in the reception antenna is a radio signal
transmitted in non-MIMO, when the specific data mapped in the block
to perform wireless transmission in MIMO in the communicating party
(transmitting side) is transmitted as a radio signal in non-MIMO,
it is possible to demodulate the specific data either in MIMO or
non-MIMO. As a result, without making a modification to the block
(Chunk) structure currently proposed by 3GPP, it is possible to
construct a system that does not require the advance information to
notify whether transmission is in MIMO or non-MIMO.
[0061] (12) Further, a wireless receiving apparatus according to
the invention is a wireless receiving apparatus that notifies a
communicating parry of reception quality of a radio signal
transmitted from each transmission antenna of the communicating
party for each transmission antenna, and the propagation path
estimating section is characterized by using a propagation path
estimation value calculated using a pilot signal transmitted from a
single or a plurality of antennas with the reception quality
measurement result being good in compensating the specific data for
the propagation path.
[0062] Thus, a propagation path estimation value calculated using a
pilot signal transmitted from a single or plurality of antennas
with the reception quality measurement result being good is used in
compensating the specific data for the propagation path, and it is
thus possible to enhance accuracy in propagation path estimation.
Further, by performing estimation of the propagation path while
assuming that a radio signal received in the reception antenna is a
radio signal transmitted in non-MIMO, when the specific data mapped
in the block to perform wireless transmission in MIMO in the
communicating party (transmitting side) is transmitted as a radio
signal in non-MIMO, it is possible to demodulate the specific data
either in MIMO or non-MIMO. As a result, without making a
modification to the block (Chunk) structure currently proposed by
3GPP, it is possible to construct a system that does not require
the advance information to notify whether transmission is in MIMO
or non-MIMO.
[0063] (13) Further, a wireless communication system according to
the invention is characterized by being comprised of any one of
combinations of the described wireless transmitting apparatuses and
the described wireless receiving apparatuses.
[0064] According to this configuration, it is possible to enhance
accuracy in propagation path estimation on the receiving side.
Further, since the specific data mapped in the block to perform
wireless transmission in MIMO is transmitted as a radio signal in
non-MIMO on the transmitting side, the receiving side is capable of
demodulating the specific data either in MIMO or non-MIMO. As a
result, without making a modification to the block (Chunk)
structure currently proposed by 3GPP, the need is eliminated for
notifying advance information to notify whether transmission is in
MIMO or non-MIMO.
[0065] (14) Further, a wireless transmitting method according to
the invention is a wireless transmitting method for performing
wireless transmission in MIMO or non-MIMO on a radio frame basis
using an OFDM signal, where the radio frame is comprised of a block
or a plurality of blocks each comprised of a plurality of
sub-blocks with a sub-block as a minimum unit being defined by a
sub-channel as a frequency component corresponding to a single or a
plurality of subcarriers and a sub-slot as a time component
corresponding to a single or a plurality of OFDM symbols, and is
characterized by at least including a mapping step of performing
mapping of a pilot signal to perform propagation path estimation,
specific data, and user data, where in the mapping step, mapping is
performed so that the specific data is transmitted as a non-MIMO
signal irrespective of the MIMO block or radio frame, or non-MIMO
block or radio frame, and that an antenna that transmits the
specific data is beforehand associated with an antenna that
transmits the pilot signal to perform propagation path
estimation.
[0066] Thus, since mapping is performed so that the specific data
is transmitted in non-MIMO in the block or the radio frame
transmitted in MIMO, and that an antenna that transmits the
specific data is beforehand associated with an antenna that
transmits the pilot signal to perform propagation path estimation,
the receiving side is capable of grasping the content of the
specific data in the stage of receiving the sub-block including the
specific data. Particularly, when the specific data is mapped into
the beginning of the block, the receiving side is capable of
grasping the content indicated by the specific data only by
receiving one sub-block of the beginning. Accordingly, for example,
when the specific data includes information of a destination, it is
possible to grasp whether or not the block is to the terminal in
the stage of receiving the sub-block of the beginning, and it is
thus possible to early determine whether or not to demodulate a
subsequently arriving sub-block or block. As a result, power
reduction can be made on the receiving side. Further, when the
specific data mapped into the beginning of the block includes
information indicating whether transmission is in MIMO or non-MIMO,
the receiving side is capable of determining MIMO or non-MIMO in
the stage of receiving the specific data, and therefore, the need
is eliminated for notifying advance information to notify whether
transmission is in MIMO or non-MIMO.
[0067] (15) Further, in the wireless transmitting method according
to the invention, it is a feature that the specific data is
comprised of a plurality of same portions, and that the plurality
of same portions is transmitted from respective different antennas
when transmission is performed using a plurality of antennas.
[0068] Thus, since the specific data is comprised of a plurality of
same portions, symbol repetitions are made, and the gain can be
increased. Further, when transmission is performed using a
plurality of antennas, a plurality of same portions is transmitted
from respective different antennas, and it is thereby possible to
obtain more sophisticated diversity effect.
[0069] (16) Further, a wireless receiving method according to the
invention is a wireless receiving method for receiving an OFDM
signal wirelessly transmitted by the wireless transmitting method
as described in claim 14 or 15, and is characterized by having a
step of performing propagation path estimation using a received
pilot signal, and a step of compensating the specific data and the
user data for the propagation path from the calculated propagation
path estimation value, where the step of compensating for the
propagation path uses a propagation path estimation value
calculated using a beforehand associated pilot signal in
compensating the specific data for the propagation path.
[0070] Thus, a propagation path estimation value calculated using a
beforehand associated pilot signal is used in compensating the
specific data for the propagation path, and it is thereby possible
to enhance accuracy in propagation path estimation. Further, by
performing estimation of the propagation path while assuming that a
radio signal received in the reception antenna is a radio signal
transmitted in non-MIMO, when the specific data mapped in the block
to perform wireless transmission in MIMO in the communicating party
(transmitting side) is transmitted as a radio signal in non-MIMO,
it is possible to demodulate the specific data either in MIMO or
non-MIMO. As a result, without making a modification to the block
(Chunk) structure currently proposed by 3GPP, it is possible to
construct a system that does not require the advance information to
notify whether transmission is in MIMO or non-MIMO.
Advantageous Effect of the Invention
[0071] Thus, according to the invention, mapping is performed so
that the specific data in a block transmitted in MIMO is
transmitted as a non-MIMO signal from the same transmission antenna
as that for the beforehand associated pilot signal, and the
receiving side is thereby capable of performing propagation path
estimation of the specific data using the pilot signal associated
with the specific data in the stage of receiving a sub-slot
including the specific data, and grasping the content of the
specific data using non-MIMO demodulation means. Particularly, when
the specific data is mapped into the beginning of the block, the
receiving side is capable of grasping the content indicated by the
specific data only by receiving one sub-block of the beginning.
Accordingly, for example, when the specific data includes
information of a destination, it is possible to grasp whether or
not the block is to the terminal in the stage of receiving the
sub-block of the beginning, and it is thus possible to early
determine whether or not to demodulate a subsequently arriving
sub-block or block. As a result, power reduction can be made on the
receiving side. Further, when the specific data mapped into the
beginning of the block includes information indicating whether
transmission is in MIMO or non-MIMO, the receiving side is capable
of determining MIMO or non-MIMO in the stage of receiving the
specific data, and therefore, the need is eliminated for notifying
advance information to notify whether the block is transmitted in
MIMO or non-MIMO.
BRIEF DESCRIPTION OF DRAWINGS
[0072] FIG. 1 is a block diagram showing a schematic configuration
of a transmitter in the present invention;
[0073] FIG. 2 is a block diagram showing a schematic configuration
of a receiver according to embodiments of the invention;
[0074] FIGS. 3A and 3B are diagrams showing block structures in the
embodiments of the invention;
[0075] FIGS. 4A and 4B are diagrams showing block structures in the
first embodiment;
[0076] FIGS. 5A and 5B are diagrams showing block structures in the
second embodiment;
[0077] FIGS. 6A and 6B are diagrams showing block structures in the
third embodiment;
[0078] FIGS. 7A and 7B are diagrams showing block structures in the
fourth embodiment;
[0079] FIGS. 8A and 8B are diagrams showing block structures in the
fifth embodiment;
[0080] FIGS. 9A and 9B are diagrams showing block structures in the
sixth embodiment;
[0081] FIG. 10 is a block diagram showing a schematic configuration
of a transmitter according to the sixth embodiment;
[0082] FIGS. 11A and 11B are another diagrams showing block
structures in the sixth embodiment;
[0083] FIG. 12 is a diagram showing an example of a data
demodulation circuit;
[0084] FIGS. 13A and 13B are another diagrams showing block
structures in the sixth embodiment;
[0085] FIG. 14A is a diagram showing allocation of pilot signals P
and shared control information S1 and S2 in non-MIMO, FIG. 14B is a
diagram showing a state where pilot signals P and shared control
information S1 and S2 are allocated to be orthogonal for each
transmission antenna, FIG. 14C is a diagram showing generalized
processing in FIG. 14B;
[0086] FIG. 15 is a diagram showing a configuration example of a
downlink radio frame assumed based on the proposal of 3GPP in
EUTRA;
[0087] FIG. 16 is a diagram showing a configuration of sub-blocks
in a block;
[0088] FIGS. 17A and 17B are diagrams showing a block extracted
from the downlink radio frame assumed based on the proposal of 3GPP
in EUTRA;
[0089] FIG. 18 is a concept diagram of a communication system using
the MIMO technique;
[0090] FIG. 19 is a diagram showing pilot allocation in MIMO;
[0091] FIG. 20 is a diagram showing a configuration of one block
for each antenna in using the MIMO technique;
[0092] FIG. 21 is a block diagram showing a schematic configuration
of a conventional transmitter;
[0093] FIG. 22 is a block diagram showing a schematic configuration
of a receiver;
[0094] FIG. 23 is another block diagram showing a schematic
configuration of a receiver; and
[0095] FIGS. 24A and 24B are diagrams showing the method of
calculating an estimation value in the conventional propagation
path estimating circuit.
DESCRIPTION OF SYMBOLS
[0096] 1-1 to 1-N First to Nth reception antennas [0097] 2-1 to 2-N
Frequency conversion circuit [0098] 3-1 to 3-N A/D conversion
circuit [0099] 4-1 to 4-N T/F transform circuit [0100] 5
Propagation path estimating circuit [0101] 6 Propagation path
compensating circuit [0102] 7 Data demodulation circuit [0103] 7a
Divider [0104] 7b Combiner [0105] 7c Demodulator [0106] 7d Decoder
[0107] 8 MLD circuit [0108] 9 Selector [0109] 10 Judging circuit
[0110] 110-1 to 110-n Mapping circuit [0111] 110a Selector [0112]
110b-1 to 110b-M Memory [0113] 110c Splitter [0114] 110d Duplicator
[0115] 111-1 to 111-M F/T transform circuit [0116] 112-1 to 112-M
D/A conversion circuit [0117] 113-1 to 113-M Frequency conversion
circuit [0118] 114-1 to 114-M First to Mth transmission
antennas
BEST MODE FOR CARRYING OUT THE INVENTION
[0119] Embodiments of the invention will be described below with
reference to accompanying drawings. First, FIG. 1 shows a wireless
transmitter according to the embodiments of the invention. As shown
in FIG. 1, in each of mapping circuits 110-1 to 110-n, pilot
signals and shared control information are allocated to memories
110b-1 to 110b-M for respective antennas to be a block structure as
described later by a selector 110a, and user data is distributed to
the memories 110b-1 to 110b-M for respective antennas by a splitter
110c. Further, F/T transform circuits 111-1 to 111-M are provided
for each transmission antenna, and transform the signals allocated
in each of the mapping circuits 110-1 to 110-n from the signals in
the frequency domain to the signals in the time domain by IFFT
computation, starting with the beginning of the frame. D/A
conversion circuits 112-1 to 112-M are provided for each
transmission antenna, and convert the digital signals in the time
domain output from F/T transform circuits 111-1 to 111-M into
analog signals, respectively. Further, frequency conversion
circuits 113-1 to 113-M are provided for each transmission antenna,
and convert the signals output from D/A conversion circuits 112-1
to 112-M into signals with the frequency to transmit, and the
signals are transmitted from transmission antennas 114-1 to 114-M,
respectively.
[0120] Next, a wireless receiver according to the embodiments of
the invention adopts a configuration as shown in FIG. 2. In other
words, as shown in FIG. 2, radio signals received in a first
reception antenna 1-1 to Nth reception antenna 1-N are respectively
input to frequency conversion circuits 2-1 to 2-N and converted
into signals with the intermediate frequency. The analog signals
with the intermediate frequency converted in the frequency
conversion circuits 2-1 to 2-N are converted into digital signals
in A/D conversion circuits 3-1 to 3-N, respectively. Further, the
digital signals in the time domain converted in the A/D conversion
circuits 3-1 to 3-N are subjected to FFT processing in T/F
transform circuits 4-1 to 4-N and thereby transformed into signals
in the frequency domain.
[0121] A propagation path estimating circuit 5 regards a radio
signal received in the first antenna 1-1 as a signal in non-MIMO,
and obtains a propagation path estimation value by a method as
described later. Further, a propagation path compensating circuit 6
regards the radio signal received in the first antenna 1-1 as a
signal in non-MIMO, and using the estimation value calculated in
the propagation path estimating circuit 5, compensates the signal
transformed in the T/F transform circuit 4-1 to be a previous
signal that is not varied on the propagation path. A data
demodulation circuit 7 demodulates the data signal compensated in
the propagation path compensating circuit 6. A judging circuit 10
controls a selector 9 based on the shared control information
demodulated in the data demodulation circuit 7, and outputs an
output signal from an MLD circuit 8 as reception data when the
received block is MIMO, while outputting an output signal from the
data demodulation circuit 7 as reception data when the received
block is non-MIMO. The MLD circuit 8 regards output signals from
the T/F transform circuits 4-1 to 4-N for each reception antenna as
MIMO signals, and performs demodulation processing.
[0122] In addition, herein, the signal received in the first
reception antenna 1-1 is used for signal input in non-MIMO, but a
signal received in another reception antenna may be used, or
signals received in a plurality of antennas may be combined to be
used. Further, herein, for the received signal, the shared control
information is demodulated in the non-MIMO demodulation circuit to
switch between MIMO and non-MIMO, but the operation of an
unnecessary circuit not used in demodulation may be halted
according to a result of judgment on MIMO or non-MIMO in the
judging circuit 10.
[0123] Hereinafter, described is the operation of the mapping
circuits in non-MIMO that is common in each embodiment, and then,
each embodiment describes the operation of the mapping circuits in
MIMO and the propagation path estimating method of the propagation
path estimating circuit of the receiver.
[0124] For example, herein, when the number of transmission
antennas is four, the mapping circuits in non-MIMO in the
embodiments of the invention operate as described below.
(1) When a transmission antenna to transmit a non-MIMO signal is
only the second transmission antenna 114-2, and transmission is
performed in the block structure of FIG. 17A with the number of
sub-channels being eight (f=8) and the number of sub-slots being
six (t=6) in a block, the circuits operate so that block
configurations for each transmission antenna are as shown in FIG.
3A. In other words, the second transmission antenna only transmits
the pilot signal, shared control information and user data, and the
other transmission antennas transmit null symbols (actually, do not
transmit data).
[0125] Further, as another example, the circuits may operate as
described below.
(2) When all the transmission antennas are transmission antennas to
transmit non-MIMO signals, the circuits operate so that block
configurations for each transmission antenna are as shown in FIG.
3B. In other words, all the transmission antennas transmit the
pilot signal, shared control information and user data in the same
configurations.
[0126] That is, when the shared control information, user data and
pilot signals are allocated in the configuration C(f,t), block
configurations of transmission antennas that transmit non-MIMO
signals are all controlled to be replicas of the aforementioned
configuration C(f,t), and block configurations of the other
transmission antennas are controlled so that nulls are
allocated.
First Embodiment
[0127] Described next are the mapping circuits 110-1 to 110-n in
MIMO of the transmitter according to the first embodiment as shown
in FIG. 1 and the propagation path estimating circuit 5 of the
receiver as shown in FIG. 2, with reference to drawings. For
example, the following conditions are determined herein.
(1) Two transmission antennas (M=2); and (2) Eight sub-channels
(f=8) and six sub-slots (t=6) in a block.
[0128] On the aforementioned conditions with the block structure of
FIG. 17A, the mapping circuits 110-1 to 110-n of the transmitter
according to the first embodiment operate so that block
configurations for each transmission antenna are as shown in FIG.
4A. Further, on the aforementioned conditions with the block
structure of FIG. 17B, the mapping circuits operate so that block
configurations for each transmission antenna are as shown in FIG.
4B. The operations of the mapping circuits 110-1 to 110-n will
specifically be described below.
[0129] The mapping operation as shown in FIG. 4A is performed as
described below.
(1) In the block structure of FIG. 17A, C(1,1), C(3,1), C(5,1) and
C(7,1) are used for allocation of pilot signals. In order for the
pilot signals not to overlap for each transmission antenna, pilot
signals of the first transmission antenna are allocated to C1(1,1)
and C1(5,1), and pilot signals of the second transmission antenna
are allocated to C2(3,1) and C2(7,1). Nulls are allocated to
C2(1,1), C2(5,1), C1(3,1) and C1(7,1). (2) In the above-mentioned
block structure, C(2,1), C(4,1), C(6,1) and C(8,1) are used for
allocation of the shared control information. Among them, the
shared control information is allocated to C1(2,1) and C1(6,1)
close to the pilot signals of the first transmission antenna, and
C2(4,1) and C2(8,1) close to the pilot signals of the second
transmission antenna, and nulls are allocated to C2(2,1), C2(6,1),
C1(4,1) and C1(8,1). (3) User data is sequentially allocated to
C1(f, t) and C2(f, t) used for allocation of the user data in the
configuration of each transmission antenna.
[0130] Meanwhile, the mapping operation as shown in FIG. 4B is
performed as described below.
(1) In the block structure of FIG. 17B, C(1,1), C(3,4), C(5,1) and
C(7,4) are used for allocation of pilot signals. In order for the
pilot signals not to overlap for each transmission antenna, pilot
signals of the first transmission antenna are allocated to C1(1,1)
and C1(3,4), and pilot signals of the second transmission antenna
are allocated to C2(5,1) and C2(7,4). Nulls are allocated to
C2(1,1), C2(3,4), C1(5,1) and C1(7,4). (2) In the above-mentioned
block structure, C(2,1), C(4,1), C(6,1) and C(8,1) are used for
allocation of the shared control information. Among them, the
shared control information is allocated to C1(2,1) close to the
pilot signal of the first transmission antenna, and C2(4,1),
C2(6,1) and C2(8,1) close to the pilot signals of the second
transmission antenna, and nulls are allocated to C2(2,1), C1(4,1),
C1(6,1) and C1(8,1). (3) User data is sequentially allocated to
C1(f, t) and C2(f, t) used for allocation of the user data in the
configuration of each transmission antenna.
[0131] In other words, the mapping circuits 110-1 to 110-n
according to the first embodiment are characterized by performing
the operations so that:
(1) pilot signals are arranged in each configuration not to overlap
for each transmission antenna because the pilot signals for each
transmission antenna are required to demodulate MIMO signals; (2)
the shared control information is arranged in a configuration of
the transmission antenna of the pilot signal nearest on the
frequency axis, where when distances from pilot signals of a
plurality of transmission antennas are the same as one another, a
transmission antenna with a smaller value of f is selected; and
that (3) the user data is arranged in the configuration of each
transmission antenna as MIMO signals.
[0132] Described next is the propagation path estimating circuit 5
of the receiver according to the first embodiment. In the block
structure as shown in FIG. 17A, the circuit 5 performs the
operation as described below.
(1) Since C(1,1), C(3,1), C(5,1) and C(7,1) are pilot signals among
first sub-slot C(1,1) to C(8,1) of the block transformed in the T/F
transform circuit 4-1, the circuit 5 obtains a propagation path
estimation value of each of the pilot signals from the difference
between the phaseamplitude information of the known pilot signal
and the phaseamplitude of received C(1,1), C(3,1), C(5,1) or
C(7,1). (2) By assuming that a propagation path of a sub-channel
near a pilot signal is the same as the propagation path of the
pilot signal, propagation path estimation values are obtained on
C(2,1), C(4,1), C(6,1) and C(8,1) in which the shared control
information is arranged. Herein, when distances from a plurality of
pilot signals are the same as one another, by assuming that the
propagation path is the same as the propagation path of a pilot
signal with a smaller value of f in C(f,1), thereby assuming that
the propagation path of C(2,1) is the same as that of C(1,1), and
that similarly, the propagation paths of C(4,1), C(6,1) and C(8,1)
are respectively the same as those of C(3,1), C(5,1) and C(7,1),
the circuit 5 obtains the propagation path estimation value of the
shared control information.
[0133] In the block structure as shown in FIG. 17B, the circuit 5
performs the operation as described below.
(1) Since C(1,1) and C(5,1) are pilot signals among first sub-slot
C(1,1) to C(8,1) of the block transformed in the T/F transform
circuit 4-1, the circuit 5 obtains a propagation path estimation
value of each of the pilot signals from the difference between the
phaseamplitude information of the known pilot signal and the
phaseamplitude of received C(1,1) or C(5,1). (2) As in the case of
FIG. 17A, by assuming that the propagation path of C(2,1) is the
same as that of C(1,1), and that similarly, the propagation paths
of C(4,1), C(6,1) and C(8,1) are the same as that of C(5,1), the
circuit 5 obtains the estimation value.
[0134] In other words, the propagation path estimating circuit 5 in
the first embodiment is characterized by performing the operation
of:
(1) estimating the propagation path of a sub-channel from a signal
of the sub-channel in which a pilot signal is arranged and the
phaseamplitude information of the known pilot signal, when first
sub-slot C(f, 1) of the block transformed in the T/F transform
circuit 4-1 is input to the propagation path estimating circuit 5;
and (2) by assuming that a propagation path of a sub-channel near a
pilot signal is the same as the propagation path of the sub-channel
in which the pilot signal is arranged, obtaining a propagation path
estimation value of the sub-channel in which the shared control
information is arranged.
[0135] Further, when the circuit 5 performs propagation path
compensation of the sub-slot at the beginning of the block using
the above-mentioned propagation path estimation value, and is
notified that the block is a non-MIMO block from the judging
circuit 10 after demodulating the shared control information, the
circuit 5 may perform propagation path estimation of a user data
portion by the same method as the conventional method.
[0136] As described above, by using the mapping circuits 110-1 to
110-n and the propagation path estimating circuit 5 according to
the first embodiment, when the transmitter according to the first
embodiment is applied to the base station, the shared control
information is transmitted as a non-MIMO signal in both the
non-MIMO block and the MIMO block. In addition, in the MIMO block,
the shared control information is transmitted from one specific
antenna selected from among a plurality of transmission antennas by
the mapping circuits 110-1 to 110-n.
[0137] Further, when the receiver according to the first embodiment
is applied to the terminal, the shared control information
contained in the sub-slot at the beginning of the block is
demodulated as a non-MIMO signal. At this point, by using the
estimation value calculated using the above-mentioned propagation
path estimating circuit 5 in propagation path compensation, the
terminal is capable of compensating the shared control information
transmitted from the same transmission antenna as that of a pilot
signal in a MIMO block using the pilot signal for each transmission
antenna, while in a non-MIMO block, being capable of compensating
by the same technique because the non-MIMO block is thought to be
the case of one transmission antenna in a MIMO block.
[0138] Accordingly, it is possible to perform propagation path
compensation without distinguishing between the non-MIMO block and
MIMO block. In other words, in order to eliminate the advance
information on whether a block to demodulate is MIMO or not,
although such a mechanism is required that common shared control
information demodulation is performed in non-MIMO and MIMO, by
performing transmission and reception with the transmitter and
receiver using the above-mentioned mapping circuits 110-1 to 110-n
and propagation path estimating circuit 5, it is possible to
eliminate the advance information on whether a block is transmitted
in MIMO or non-MIMO notified prior to demodulation of the block,
without modifying the block structure currently proposed by
3GPP.
[0139] Further, when the first embodiment is adopted, since pilot
signals required to perform propagation path compensation of a
sub-slot including the shared control information are all included
in the sub-slot, the need of a buffer is eliminated for storing
information of a plurality of sub-slots until pilot signals are all
obtained, it is possible to early demodulate the shared control
information, and the circuit scale can be reduced because a buffer
is not necessary.
Second Embodiment
[0140] Described below are the mapping circuits 110-1 to 110-n in
MIMO of the transmitter and the propagation path estimating circuit
5 of the receiver according to the second embodiment with reference
to drawings. Herein, for example, following conditions are
determined.
(1) Four transmission antennas (M=4); and (2) In a block, the
number of sub-channels is eight (f=8), the number of sub-slots is
six (t=6), and further, when different modulation schemes are used
for each antenna in MIMO, the terminal usually notifies the base
station of channel reception quality information for each
transmission antenna. As the reception quality herein, considered
specifically are SNR (Signal to Noise Ratio), SINR (Signal to
Interference and Noise Ratio), BER (Bit Error Rate) and the
like.
[0141] In the second embodiment, it is assumed that the reception
quality is better in the order of the first transmission antenna,
the third transmission antenna, the second transmission antenna,
and the fourth transmission antenna (the first transmission antenna
provides the best reception quality, while the fourth transmission
antenna provides the worst reception quality).
[0142] On the aforementioned conditions with the block structure of
FIG. 17A, the mapping circuits 110-1 to 110-n of the transmitter
used in the second embodiment operate so that block configurations
for each transmission antenna are as shown in FIG. 5A. Further, on
the aforementioned conditions with the block structure of FIG. 17B,
the mapping circuits operate so that block configurations for each
transmission antenna are as shown in FIG. 5B. The operations of the
mapping circuits 110-1 to 110-n will specifically be described
below.
[0143] The mapping operation as shown in FIG. 5A is performed as
described below.
(1) A pilot signal of the first transmission antenna is allocated
to C1(1,1), a pilot signal of the second transmission antenna is
allocated to C2(3,1), a pilot signal of the third transmission
antenna is allocated to C3(5,1) and a pilot signal of the fourth
transmission antenna is allocated to C4(7,1). Nulls are allocated
to Cm(1,1)(m=2, 3, 4), Cm(3,1)(m=1, 3, 4), Cm(5,1)(m=1, 2, 4) and
Cm(7,1)(m=1, 2, 3). (2) In the above-mentioned block structure,
C(2,1), C(4,1), C(6,1) and C(8,1) are used for allocation of the
shared control information. Among the transmission antennas of the
pilot signals allocated to the sub-slot including the shared
control information, the same shared control information is
arranged in the configuration(s) of a single or plurality of
transmission antennas providing good reception quality in the
terminal. Herein, pilot signals allocated to the sub-slot including
the shared control information are pilot signals of the first
transmission antenna, the second transmission antenna, the third
transmission antenna, and the fourth transmission antenna, and by
selecting two transmission antennas with good reception quality in
the terminal, the same shared control information is allocated to
C1(2,1) and C3(2,1), C1(4,1) and C3(4,1) C1(6,1) and C3(6,1), and
C1(8,1) and C3(8,1). (3) User data is sequentially allocated to
C1(f, t), C2(f, t), C3(f, t) and C4(f, t) used for allocation of
the user data in the configuration of each transmission
antenna.
[0144] Meanwhile, the mapping operation as shown in FIG. 5B is
performed as described below.
(1) A pilot signal of the first transmission antenna is allocated
to C1(1,1), a pilot signal of the second transmission antenna is
allocated to C2(5,1), a pilot signal of the third transmission
antenna is allocated to C3(3,4) and a pilot signal of the fourth
transmission antenna is allocated to C4(7,4). Nulls are allocated
to Cm(1,1)(m=2, 3, 4), Cm(5,1)(m=1, 3, 4), Cm(3,4)(m=1, 2, 4) and
Cm(7,4)(m=1, 2, 3). (2) In the above-mentioned block structure,
C(2,1), C(4,1), C(6,1) and C(8,1) are used for allocation of the
shared control information. Among the transmission antennas of the
pilot signals allocated to the sub-slot including the shared
control information, the same shared control information is
arranged in the configuration(s) of a single or plurality of
transmission antennas providing good reception quality in the
terminal. Herein, pilot signals allocated to the sub-slot including
the shared control information are pilot signals of the first
transmission antenna and the second transmission antenna, and by
selecting two transmission antennas with good reception quality in
the terminal, the same shared control information is allocated to
C1(2,1) and C2(2,1), C1(4,1) and C2(4,1), C1(6,1) and C2(6,1), and
C1(8,1) and C2(8,1). (3) User data is sequentially allocated to
C1(f, t), C2(f, t), C3(f, t) and C4(f, t) used for allocation of
the user data in the configuration of each transmission
antenna.
[0145] In other words, the mapping circuits 110-1 to 110-n
according to the second embodiment are characterized by performing
the operations so that:
(1) pilot signals are arranged in each configuration not to overlap
for each transmission antenna as in the first embodiment; (2) the
shared control information is arranged in a configuration of each
transmission antenna so that the same shared control information is
transmitted from a single or plurality of transmission antennas
(the number of selected transmission antennas is known in the base
station and terminal) providing good reception quality in the
terminal among transmission antennas of pilot signals transmitted
in the sub-slot including the shared control information; and that
(3) the user data is arranged in the configuration of each
transmission antenna as MIMO signals.
[0146] Described next is the propagation path estimating circuit 5
of the receiver according to the second embodiment. In the block
structure as shown in FIG. 17A, the circuit 5 performs the
operation as described below.
(1) Since C(1,1), C(3,1), C(5,1) and C(7,1) are pilot signals among
first sub-slot C(1,1) to C(8,1) of the block transformed in the T/F
transform circuit 4-1, the circuit 5 obtains a propagation path
estimation value of each of the pilot signals from the difference
between the phaseamplitude information of the known pilot signal
and the phaseamplitude of received C(1,1), C(3,1), C(5,1) or
C(7,1). (2) The shared control information is transmitted from two
transmission antennas with good reception quality notified to the
base station in MIMO. Accordingly, the circuit 5 obtains respective
propagation path estimation values of the shared control
information of the selected transmission antennas, combines the
obtained estimation values, and thereby obtains the propagation
path estimation value of the received shared control information.
Herein, first, using the pilot signal of C(1,1) allocated to the
first transmission antenna, the circuit 5 obtains propagation path
estimation values of C(2,1), C(4,1), C(6,1) and C(8,1). Next, using
the pilot signal of C(5,1) allocated to the third transmission
antenna, propagation path estimation values are similarly obtained.
The circuit 5 combines the estimation values of C(2,1) respectively
obtained in two transmission antennas, and thereby obtains a
propagation path estimation value of received signal C(2,1).
Similarly, the circuit 5 obtains propagation path estimation values
of C(4,1), C(6,1) and C(8,1) by combining. The same methods as
conventional methods (average, linear interpolation) can be used as
the method of obtaining an estimation value for each transmission
antenna.
[0147] Meanwhile, in the block structure as shown in FIG. 17B, the
circuit 5 performs the operation as described below.
(1) Since C(1,1) and C(5,1) are pilot signals among first sub-slot
C(1,1) to C(8,1) of the block transformed in the T/F transform
circuit 4-1, the circuit 5 obtains a propagation path estimation
value of each of the pilot signals from the difference between the
phaseamplitude information of the known pilot signal and the
phaseamplitude of received C(1,1) or C(5,1). (2) The circuit 5
obtains the propagation path estimation value as in (2) of the
block of the above-mentioned (a). Herein, using the pilot signal of
C(1,1) allocated to the first transmission antenna, the circuit 5
obtains propagation path estimation values of C1(2,1), C1(4,1),
C1(6,1) and C1(8,1). Using the pilot signal of C(5,1) allocated to
the second transmission antenna, the circuit 5 obtains propagation
path estimation values of C2(2,1), C2(4,1), C2(6,1) and C2(8,1).
The circuit 5 combines the obtained estimation values of C1(2,1)
and C2(2,1), and thereby obtains a propagation path estimation
value of received C(2,1). Similarly, the circuit 5 obtains
propagation path estimation values of C(4,1), C(6,1) and C(8,1).
The same methods as conventional methods (average, linear
interpolation) can be used as the method of obtaining an estimation
value for each transmission antenna.
[0148] In other words, the propagation path estimating circuit 5
according to the second embodiment is characterized by performing
the operation of:
(1) estimating the propagation path of a sub-channel from
differences in phase and amplitude between received signal of the
sub-channel in which a pilot signal is arranged and the known pilot
signal, when first sub-slot C(f,1) of the block transformed in the
T/F transform circuit 4-1 is input to the propagation path
estimating circuit 5; and (2) since the shared control information
is transmitted from a single or plurality of transmission antennas
with good reception quality notified to the base station, obtaining
propagation path estimation values of the shared control
information for each of the selected transmission antenna,
combining the obtained estimation values, and thereby obtaining the
propagation path estimation value of the received shared control
information.
[0149] Further, when the circuit 5 performs propagation path
compensation of the sub-slot at the beginning of the block using
the above-mentioned propagation path estimation value, and is
notified that the block is a non-MIMO block from the judging
circuit 10 after demodulating the shared control information, the
circuit 5 may perform propagation path estimation of a user data
portion by the same method as the conventional method.
[0150] As described above, by using the mapping circuits 110-1 to
110-n and the propagation path estimating circuit 5 according to
the second embodiment, when the transmitter according to the second
embodiment is applied to the base station, the shared control
information is transmitted as a non-MIMO signal in both the
non-MIMO block and the MIMO block. In addition, in the MIMO block,
for the shared control information, the same shared control
information is transmitted from all the transmission antennas of
pilot signals transmitted in a sub-slot including the shared
control information.
[0151] Further, when the receiver according to the second
embodiment is applied to the terminal, the shared control
information contained in the sub-slot at the beginning of the block
is demodulated as a non-MIMO signal. At this point, by using the
estimation value calculated using the above-mentioned propagation
path estimating circuit 5 in propagation path compensation, the
terminal is capable of compensating the shared control information
for the propagation path in a MIMO-block by using pilot signals for
each of the selected transmission antennas, obtaining variations in
phase and amplitude of each of the transmission antennas and
combining the values, and also in a non-MIMO block, capable of
compensating for the propagation path by the same technique as that
used in the case of the MIMO-block.
[0152] Accordingly, it is possible to perform propagation path
compensation of the shared control information without
distinguishing between the non-MIMO block and MIMO block. In other
words, as in the first embodiment, by performing transmission and
reception with the transmitter and receiver using the
above-mentioned mapping circuits 110-1 to 110-n and propagation
path estimating circuit 5 according to the second embodiment, it is
possible to eliminate the advance information on whether a block is
transmitted in MIMO or non-MIMO notified prior to demodulation of
the block, without modifying the block structure currently proposed
by 3GPP. Further, it is possible to early demodulate the shared
control information, and the circuit scale can be reduced because a
buffer is not necessary. Furthermore, since the shared control
information is transmitted using a transmission antenna with good
reception quality, it is possible to enhance the signal quality of
the shared control information. In addition, herein, the
transmission antenna of the shared control information is selected
based on the channel reception quality information from the
terminal, but it is also possible to use a transmission antenna
that is beforehand determined between the base station and the
terminal.
Third Embodiment
[0153] Described next are the mapping circuits 110-1 to 110-n in
MIMO of the transmitter and the propagation path estimating circuit
5 of the receiver according to the third embodiment of the
invention, with reference to drawings. Also herein, for example,
the following conditions are determined as in the first
embodiment.
(1) Two transmission antennas (M=2); and (2) Eight sub-channels
(f=8) and six sub-slots (t=6) in a block.
[0154] On the aforementioned conditions with the block structure of
FIG. 17A, the mapping circuits 110-1 to 110-n of the transmitter
according to the third embodiment operate so that block
configurations for each antenna are as shown in FIG. 6A. Further,
on the aforementioned conditions with the block structure of FIG.
17B, the mapping circuits operate so that block configurations for
each antenna are as shown in FIG. 6B. The operations of the mapping
circuits 110-1 to 110-n will specifically be described.
[0155] The mapping operation as shown in FIG. 6A is performed as
described below.
(1) As in the first embodiment, pilot signals of the first
transmission antenna are allocated to C1(1,1) and C1(5,1), and
pilot signals of the second transmission antenna are allocated to
C2(3,1) and C2(7,1). Nulls are allocated to C2(1,1), C2(5,1),
C1(3,1) and C1(7,1). (2) In the above-mentioned block structure,
C(2,1), C(4,1), C(6,1) and C(8,1) are used for allocation of the
shared control information, and by using the first transmission
antenna as an antenna that is beforehand determined between the
base station and the terminal to allocate the shared control
information, the shared control information is allocated to
C1(2,1), C1(4,1), C1(6,1) and C1(8,1), while nulls are allocated to
C2(2,1), C2(4,1), C2(6,1) and C2(8,1). (3) User data is
sequentially allocated to C1(f, t) and C2(f, t) used for allocation
of the user data in the configuration of each transmission
antenna.
[0156] Meanwhile, the mapping operation as shown in FIG. 6B is
performed as described below.
(1) As in the first embodiment, pilot signals of the first
transmission antenna are allocated to C1(1,1) and C1(3,4), and
pilot signals of the second transmission antenna are allocated to
C2(5,1) and C2(7,4). Nulls are allocated to C2(1,1), C2(3,4),
C1(5,1) and C1(7,4). (2) As in FIG. 6A, the shared control
information is allocated to C1(2,1), C1(4,1), C1(6,1) and C1(8,1),
and nulls are allocated to C2(2,1), C2(4,1), C2(6,1) and C2(8,1).
(3) User data is sequentially allocated to C1(f, t) and C2(f, t)
used for allocation of the user data in the configuration of each
transmission antenna.
[0157] In other words, the mapping circuits 110-1 to 110-n
according to the third embodiment are characterized by performing
the operations so that:
(1) pilot signals are arranged in each configuration not to overlap
for each transmission antenna as in the first embodiment; (2) the
shared control information is arranged in a configuration of the
transmission antenna that is beforehand determined between the base
station and the terminal by any means; and that (3) the user data
is arranged in the configuration of each transmission antenna as
MIMO signals.
[0158] Described next is the propagation path estimating circuit 5
of the receiver according to the third embodiment. In the block
structure as shown in FIG. 17A, the circuit 5 performs the
operation as described below.
(1) Since C(1,1), C(3,1), C(5,1) and C(7,1) are pilot signals among
first sub-slot C(1,1) to C(8,1) of the block transformed in the T/F
transform circuit 4-1, the circuit 5 obtains a propagation path
estimation value of each of the pilot signals from the difference
between the phaseamplitude information of the known pilot signal
and the phaseamplitude of received C(1,1), C(3,1), C(5,1) or
C(7,1). (2) The propagation path estimation value of the shared
control information is obtained using the propagation path
estimation value of the pilot signal of the beforehand determined
transmission antenna. Herein, using only the pilot signals of
C(1,1) and C(5,1) allocated to the first transmission antenna, the
circuit 5 obtains propagation path estimation values of C(2,1),
C(4,1), C(6,1) and C(8,1) in which the shared control information
is arranged. The same methods as conventional methods (average,
linear interpolation) can be used as the method of obtaining an
estimation value.
[0159] Meanwhile, in the block structure as shown in FIG. 17B, the
circuit 5 performs the operation as described below.
(1) Since C(1,1) and C(5,1) are pilot signals among first sub-slot
C(1,1) to C(8,1) of the block transformed in the T/F transform
circuit 4-1, the circuit 5 obtains a propagation path estimation
value of each of the pilot signals from the difference between the
phaseamplitude information of the known pilot signal and the
phaseamplitude of received C(1,1) or C(5,1). (2) The propagation
path estimation value of the shared control information is obtained
using the propagation path estimation value of the pilot signal of
the beforehand determined transmission antenna. Herein, using only
the pilot signal of C(1,1) allocated to the first transmission
antenna, the circuit 5 obtains propagation path estimation values
of C(2,1), C(4,1), C(6,1) and C(8,1) in which the shared control
information is arranged. The same methods as conventional methods
(average, linear interpolation) can be used as the method of
obtaining an estimation value.
[0160] In other words, the propagation path estimating circuit 5 in
the third embodiment is characterized by performing the operation
of:
(1) estimating the propagation path of a sub-channel from
differences in phase and amplitude between a received signal of the
sub-channel in which a pilot signal is arranged and the known pilot
signal, when first sub-slot C(f,1) of the block transformed in the
T/F transform circuit 4-1 is input to the propagation path
estimating circuit 5; and (2) by using only pilot signals in a
configuration where the pilot signals of a beforehand determined
transmission antenna are arranged in MIMO, obtaining propagation
path estimation values of sub-channels in which the shared control
information is arranged.
[0161] Further, when the circuit 5 performs propagation path
compensation of the sub-slot at the beginning of the block using
the above-mentioned propagation path estimation value, and is
notified that the block is a non-MIMO block from the judging
circuit 10 after demodulating the shared control information, the
circuit 5 may perform propagation path estimation of a user data
portion by the same method as the conventional method.
[0162] By using the mapping circuits 110-1 to 110-n and the
propagation path estimating circuit 5 according to the third
embodiment, when the transmitter according to the third embodiment
is applied to the base station, the shared control information is
transmitted as a non-MIMO signal in both the non-MIMO block and the
MIMO block. In addition, in the MIMO block, the shared control
information is transmitted from one specific antenna selected from
a plurality of transmission antennas by the mapping circuits 110-1
to 110-n.
[0163] Further, when the receiver according to the third embodiment
is applied to the terminal, the shared control information
contained in the sub-slot at the beginning of the block is
demodulated as a non-MIMO signal. At this point, by using the
estimation value calculated using the above-mentioned propagation
path estimating circuit 5 in propagation path compensation, the
terminal is capable of compensating for the propagation path in a
MIMO block by using pilot signals of an antenna that transmits the
shared control information, and in a non-MIMO block, capable of
estimating the propagation path using only the pilot signals used
in the MIMO-block, while originally being capable of estimating the
propagation path using all the pilot signals.
[0164] Accordingly, it is possible to perform propagation path
compensation without distinguishing between the non-MIMO block and
MIMO block. In other words, as in the first embodiment, by
performing transmission and reception with the transmitter and
receiver using the above-mentioned mapping circuits 110-1 to 110-n
and propagation path estimating circuit 5 according to the third
embodiment, it is possible to eliminate the advance information on
whether a block is transmitted in MIMO or non-MIMO notified prior
to demodulation of the block, without modifying the block structure
currently proposed by 3GPP. Further, it is possible to early
demodulate the shared control information, and the circuit scale
can be reduced because a buffer is not necessary.
Fourth Embodiment
[0165] Described below are the mapping circuits 110-1 to 110-n in
MIMO of the transmitter and the propagation path estimating circuit
5 of the receiver according to the fourth embodiment of the
invention, with reference to drawings. Also herein, for example,
the following conditions are determined as in the third
embodiment.
(1) Two transmission antennas (M=2); and (2) Eight sub-channels
(f=8) and six sub-slots (t=6) in a block.
[0166] On the aforementioned conditions with the block structure of
FIG. 17A, the mapping circuits 110-1 to 110-n of the transmitter
according to the fourth embodiment operate so that block
configurations for each transmission antenna are as shown in FIG.
7A. Further, on the aforementioned conditions with the block
structure of FIG. 17B, the mapping circuits operate so that block
configurations for each transmission antenna are as shown in FIG.
7B. The operations of the mapping circuits 110-1 to 110-n will
specifically be described below.
[0167] The mapping operation as shown in FIG. 7A is performed as
described below.
(1) As in the third embodiment, pilot signals of the first
transmission antenna are allocated to C1(1,1) and C1(5,1), and
pilot signals of the second transmission antenna are allocated to
C2(3,1) and C2(7,1). Nulls are allocated to C2(1,1), C2(5,1),
C1(3,1) and C1(7,1). (2) In the above-mentioned block structure,
C(2,1), C(4,1), C(6,1) and C(8,1) are used for allocation of the
shared control information. The same shared control information is
arranged in all the configurations of transmission antennas of the
pilot signals allocated to a sub-slot including the shared control
information. Herein, since pilot signals allocated to the sub-slot
including the shared control information are pilot signals of the
first transmission antenna and the second transmission antenna, the
same shared control information is allocated to C1(2,1) and
C2(2,1), C1(4,1) and C2(4,1), C1(6,1) and C2(6,1), and C1(8,1) and
C2(8,1). (3) User data is sequentially allocated to C1(f, t), and
C2(f, t) used for allocation of the user data in the configuration
of each transmission antenna.
[0168] Meanwhile, the mapping operation as shown in FIG. 7B is
performed as described below.
(1) As in the third embodiment, pilot signals of the first
transmission antenna are allocated to C1(1,1) and C1(3,4), and
pilot signals of the second transmission antenna are allocated to
C2(5,1) and C2(7,4). Nulls are allocated to C2(1,1), C2(3,4),
C1(5,1) and C1(7,4). (2) As in FIG. 7A, the same shared control
information is allocated to C1(2,1) and C2(2,1), C1(4,1) and
C2(4,1), C1(6,1) and C2(6,1), and C1(8,1) and C2(8,1). (3) User
data is sequentially allocated to C1(f, t), and C2(f, t) used for
allocation of the user data in the configuration of each
transmission antenna.
[0169] In other words, the mapping circuits 110-1 to 110-n
according to the fourth embodiment are characterized by performing
the operations so that:
(1) pilot signals are arranged in each configuration not to overlap
for each transmission antenna as in the first embodiment; (2) the
shared control information is arranged in a configuration of each
transmission antenna so that the same shared control information is
transmitted from all the transmission antennas of pilot signals
transmitted in the sub-slot including the shared control
information; and that (3) the user data is arranged in the
configuration of each transmission antenna as MIMO signals.
[0170] Described next is the propagation path estimating circuit 5
of the receiver according to the fourth embodiment. In the block
structure as shown in FIG. 17A, the circuit 5 performs the
operation as described below.
(1) Since C(1,1), C(3,1), C(5,1) and C(7,1) are pilot signals among
first sub-slot C(1,1) to C(8,1) of the block transformed in the T/F
transform circuit 4-1, the circuit 5 obtains a propagation path
estimation value of each of the pilot signals from the difference
between the phaseamplitude information of the known pilot signal
and the phaseamplitude of received C(1,1), C(3,1), C(5,1) or
C(7,1). (2) The propagation path estimation value of the shared
control information is considered a combined value of propagation
path estimation values for each transmission antenna arranged by
the above-mentioned mapping circuits 110-1 to 110-n. Accordingly,
the circuit 5 obtains propagation path estimation values of the
shared control information for each transmission antenna, combines
the obtained estimation values, and thereby obtains the propagation
path estimation value of the received shared control information.
Herein, first, using the pilot signals of C(1,1) and C(5,1)
allocated to the first transmission antenna, the circuit 5 obtains
propagation path estimation values of C(2,1), C(4,1), C(6,1) and
C(8,1). Next, using the pilot signals of C(3,1) and C(7,1)
allocated to the second transmission antenna, propagation path
estimation values are similarly obtained. The circuit 5 combines
the estimation values of C(2,1) respectively obtained in two
transmission antennas, and thereby obtains a propagation path
estimation value of received C(2,1). Similarly, the circuit 5
obtains propagation path estimation values of C(4,1), C(6,1) and
C(8,1) by combining. The same methods as conventional methods
(average, linear interpolation) can be used as the method of
obtaining an estimation value for each transmission antenna.
[0171] Meanwhile, in the block structure as shown in FIG. 17B, the
circuit 5 performs the operation as described below.
(1) Since C(1,1) and C(5,1) are pilot signals among first sub-slot
C(1,1) to C(8,1) of the block transformed in the T/F transform
circuit 4-1, the circuit 5 obtains a propagation path estimation
value of each of the pilot signals from the difference between the
phaseamplitude information of the known pilot signal and the
phaseamplitude of received C(1,1) or C(5,1). (2) The propagation
path estimation value of the shared control information is
considered a combined value of propagation path estimation values
for each transmission antenna arranged by the above-mentioned
mapping circuits 110-1 to 110-n. Accordingly, the circuit 5 obtains
propagation path estimation values of the shared control
information for each antenna, combines the obtained estimation
values, and thereby obtains the propagation path estimation value
of the received shared control information. Herein, using the pilot
signal of C(1,1) allocated to the first transmission antenna, the
circuit 5 obtains propagation path estimation values of C1(2,1),
C1(4,1), C1(6,1) and C1(8,1), and using the pilot signal of C(5,1)
allocated to the second transmission antenna, obtains propagation
path estimation values of C2(2,1), C2(4,1), C2(6,1) and C2(8,1).
The circuit 5 combines the estimation values of obtained C1(2,1)
and C2(2,1), and thereby obtains an estimation value of received
C(2,1). Similarly, the circuit 5 obtains propagation path
estimation values of C(4,1), C(6,1) and C(8,1). The same methods as
conventional methods (average, linear interpolation) can be used as
the method of obtaining an estimation value for each transmission
antenna.
[0172] In other words, the propagation path estimating circuit 5
according to the fourth embodiment is characterized by performing
the operation of:
(1) estimating the propagation path of a sub-channel from
differences in phase and amplitude between received signal of the
sub-channel in which a pilot signal is arranged and the known pilot
signal, when first sub-slot C(f, 1) of the block transformed in the
T/F transform circuit 4-1 is input to the propagation path
estimating circuit 5; and (2) since the propagation path estimation
value of the shared control information is considered a combined
value of propagation path estimation values for each transmission
antenna arranged by the above-mentioned mapping circuits 110-1 to
110-n, obtaining propagation path estimation values of the shared
control information for each transmission antenna, combining the
obtained estimation values, and thereby obtaining the propagation
path estimation value of the received shared control
information.
[0173] Further, when the circuit 5 performs propagation path
compensation of the sub-slot at the beginning of the block using
the above-mentioned propagation path estimation value, and is
notified that the block is a non-MIMO block from the judging
circuit 10 after demodulating the shared control information, the
circuit 5 may perform propagation path estimation of a user data
portion by the same method as the conventional method.
[0174] By using the mapping circuits 110-1 to 110-n and the
propagation path estimating circuit 5 according to the fourth
embodiment, when the transmitter according to the fourth embodiment
is applied to the base station, the shared control information is
transmitted as a non-MIMO signal in both the non-MIMO block and the
MIMO block. In addition, in the MIMO block, for the shared control
information, the same shared control information is transmitted
from all the transmission antennas of pilot signals transmitted in
a sub-slot including the shared control information.
[0175] Further, when the receiver according to the fourth
embodiment is applied to the terminal, the shared control
information contained in the sub-slot at the beginning of the block
is demodulated as a non-MIMO signal. At this point, by using the
estimation value calculated using the above-mentioned propagation
path estimating circuit 5 in propagation path compensation, the
terminal is capable of compensating the shared control information
for the propagation path in a MIMO-block by using pilot signals for
each antenna, obtaining variations in phase and amplitude of each
antenna and combining the values, and also in a non-MIMO block,
capable of compensating for the propagation path by the same
technique as that used in the case of the MIMO-block.
[0176] Accordingly, it is possible to perform propagation path
compensation without distinguishing between the non-MIMO block and
MIMO block. In other words, as in the first embodiment, by
performing transmission and reception with the transmitter and
receiver using the above-mentioned mapping circuits 110-1 to 110-n
and propagation path estimating circuit 5 according to the fourth
embodiment, it is possible to eliminate the advance information on
whether a block is transmitted in MIMO or non-MIMO notified prior
to demodulation of the block, without modifying the block structure
currently proposed by 3GPP. Further, it is possible to early
demodulate the shared control information, and the circuit scale
can be reduced because a buffer is not necessary.
Fifth Embodiment
[0177] Described below are the mapping circuits 110-1 to 110-n in
MIMO of the transmitter and the propagation path estimating circuit
5 of the receiver according to the fifth embodiment, with reference
to drawings. For example, the following conditions are determined
herein.
(1) Two transmission antennas (M=2); and (2) Eight sub-channels
(f=8) and six sub-slots (t=6) in a block.
[0178] On the aforementioned conditions with the block structure of
FIG. 17A, the mapping circuits 110-1 to 110-n of the transmitter
according to the fifth embodiment operate so that block
configurations for each transmission antenna are as shown in FIG.
8A. Further, on the aforementioned conditions with the block
structure of FIG. 17B, the mapping circuits operate so that block
configurations for each transmission antenna are as shown in FIG.
8B. The operations of the mapping circuits 110-1 to 110-n will
specifically be described below.
[0179] The mapping operation as shown in FIG. 8A is performed as
described below.
(1) In the block structure of FIG. 17A, C(1,1), C(3,1), C(5,1) and
C(7,1) are used for allocation of pilot signals. In order for the
pilot signals not to overlap for each transmission antenna, pilot
signals of the first transmission antenna are allocated to C1(1,1)
and C1(5,1), and pilot signals of the second transmission antenna
are allocated to C2(3,1) and C2(7,1). Nulls are allocated to
C2(1,1), C2(5,1), C1(3,1) and C1(7,1). (2) In the above-mentioned
block structure, C(2,1), C(4,1), C(6,1) and C(8,1) are used for
allocation of the shared control information. Since a pilot signal
nearest C(2,1) on the low frequency side is C(1,1), the shared
control information is allocated to C1(2,1) so that C(2,1) is
transmitted from the first transmission antenna that transmits
C(1,1), and the null is allocated to C2(2,1). Similarly, the shared
control information is allocated to C2(4,1), C1(6,1) and C2(8,1),
and nulls are allocated to C1(4,1), C2(6,1) and C1(8,1). (3) User
data is sequentially allocated to C1(f, t) and C2(f, t) used for
allocation of the user data in the configuration of each
transmission antenna.
[0180] Meanwhile, the mapping operation as shown in FIG. 8B is
performed as described below.
(1) In the block structure of FIG. 17B, C(1,1), C(3,4), C(5,1) and
C(7,4) are used for allocation of pilot signals. In order for the
pilot signals not to overlap for each transmission antenna, pilot
signals of the first transmission antenna are allocated to C1(1,1)
and C1(3,4), and pilot signals of the second transmission antenna
are allocated to C2(5,1) and C2(7,4). Nulls are allocated to
C2(1,1), C2(3,4), C1(5,1) and C1(7,4). (2) In the above-mentioned
block structure, C(2,1), C(4,1), C(6,1) and C(8,1) are used for
allocation of the shared control information. Since a pilot signal
nearest C(2,1) on the low frequency side is C(1,1), the shared
control information is allocated to C1(2,1) so that C(2,1) is
transmitted from the first transmission antenna that transmits
C(1,1), and the null is allocated to C2(2,1). Similarly, the shared
control information is allocated to C1(4,1), C2(6,1) and C2(8,1),
and nulls are allocated to C2(4,1), C1(6,1) and C1(8,1). (3) User
data is sequentially allocated to C1(f, t) and C2(f, t) used for
allocation of the user data in the configuration of each
transmission antenna.
[0181] In other words, the mapping circuits 110-1 to 110-n
according to the fifth embodiment are characterized by performing
the operations so that:
(1) pilot signals are arranged in each configuration not to overlap
for each transmission antenna because the pilot signals for each
transmission antenna are required to demodulate MIMO signals; (2)
the shared control information is arranged in a configuration of
the transmission antenna of the pilot signal nearest on the low
frequency side in the same sub-slot; and that (3) the user data is
arranged in the configuration of each transmission antenna as MIMO
signals.
[0182] Described next is the propagation path estimating circuit 5
of the receiver according to the fifth embodiment. In the block
structure as shown in FIG. 17A, the circuit 5 performs the
operation as described below.
(1) Since C(1,1), C(3,1), C(5,1) and C(7,1) are pilot signals among
first sub-slot C(1,1) to C(8,1) of the block transformed in the T/F
transform circuit 4-1, the circuit 5 obtains a propagation path
estimation value of each of the pilot signals from the difference
between the phaseamplitude information of the known pilot signal
and the phaseamplitude of received C(1,1), C(3,1), C(5,1) or
C(7,1). (2) By assuming that a propagation path of a sub-channel
between pilot signals in the same sub-slot is the same as the
propagation path of the pilot signal on the low frequency side,
propagation path estimation values are obtained on C(2,1), C(4,1),
C(6,1) and C(8,1) in which the shared control information is
arranged.
[0183] In the block structure as shown in FIG. 17B, the circuit 5
performs the operation as described below.
(1) Since C(1,1) and C(5,1) are pilot signals among first sub-slot
C(1,1) to C(8,1) of the block transformed in the T/F transform
circuit 4-1, the circuit 5 obtains a propagation path estimation
value of each of the pilot signals from the difference between the
phaseamplitude information of the known pilot signal and the
phaseamplitude of received C(1,1) or C(5,1). (2) As in the case of
FIG. 17A, by assuming that the propagation paths of C(2,1) and
C(4,1) are the same as that of C(1,1), and that the propagation
paths of C(6,1) and C(8,1) are the same as that of C(5,1), the
circuit 5 obtains the propagation path estimation value.
[0184] In other words, the propagation path estimating circuit 5
according to the fifth embodiment is characterized by performing
the operation of:
(1) estimating the propagation path of a sub-channel from a signal
of the sub-channel in which a pilot signal is arranged and the
phaseamplitude information of the known pilot signal, when first
sub-slot C(f,1) of the block transformed in the T/F transform
circuit 4-1 is input to the propagation path estimating circuit 5;
and (2) by assuming that a propagation path of a sub-channel
between pilot signals in the same sub-slot is the same as the
propagation path of the sub-channel in which a pilot signal on the
low frequency side is arranged, obtaining propagation path
estimation values of sub-channels in which the shared control
information is arranged.
[0185] Further, when the circuit 5 performs propagation path
compensation of the sub-slot at the beginning of the block using
the above-mentioned propagation path estimation value, and is
notified that the block is a non-MIMO block from the judging
circuit 10 after demodulating the shared control information, the
circuit 5 may perform propagation path estimation of a user data
portion by the same method as the conventional method.
[0186] As described above, by using the mapping circuits 110-1 to
110-n and the propagation path estimating circuit 5 according to
the fifth embodiment, when the transmitter according to the fifth
embodiment is applied to the base station, the shared control
information is transmitted as a non-MIMO signal in both the
non-MIMO block and the MIMO block. In addition, in the MIMO block,
the shared control information is transmitted from one specific
antenna selected from a plurality of transmission antennas by the
mapping circuits 110-1 to 110-n.
[0187] Further, when the receiver according to the fifth embodiment
is applied to the terminal, the shared control information
contained in the sub-slot at the beginning of the block is
demodulated as a non-MIMO signal. At this point, by using the
estimation value calculated using the above-mentioned propagation
path estimating circuit 5 in propagation path compensation, the
terminal is capable of compensating the shared control information
transmitted from the same transmission antenna as that of a pilot
signal in a MIMO block using the pilot signal for each transmission
antenna, while in a non-MIMO block, being capable of compensating
by the same technique because the non-MIMO block is thought to be
the case of one transmission antenna in a MIMO block.
[0188] Accordingly, it is possible to perform propagation path
compensation without distinguishing between the non-MIMO block and
MIMO block. In other words, as in the first embodiment, by
performing transmission and reception with the transmitter and
receiver using the mapping circuits 110-1 to 110-n and propagation
path estimating circuit 5 according to the fifth embodiment, it is
possible to eliminate the advance information on whether a block is
transmitted in MIMO or non-MIMO notified prior to demodulation of
the block, without modifying the block structure currently proposed
by 3GPP. Further, it is possible to early demodulate the shared
control information, and the circuit scale can be reduced because a
buffer is not necessary.
Sixth Embodiment
[0189] Described below are the mapping circuits 110-1 to 110-n of
the transmitter and the receiver according to the sixth embodiment,
with reference to drawings.
[0190] In the first embodiment as described previously, for
example, the shared control information S input to the mapping
circuits 110-1 in the transmitter in FIG. 1 is divided into S1 to
S4, and when the allocation as shown in FIG. 9A is performed in
non-MIMO, by allocating S1 to C1(2,1), S2 to C2(4,1), S3 to C1(6,1)
and S4 to C2(8,1) in MIMO as shown in FIG. 9B, it is controlled
that the shared control information received in the receiver has
the same known allocation in the transmitter and receiver in MIMO
and non-MIMO.
[0191] The operations of the mapping circuits in the sixth
embodiment differ from those of the first embodiment only in
division and allocation of the shared control information, and
descriptions except the division and allocation of the shared
control information are omitted.
[0192] FIG. 10 is a block diagram illustrating a schematic
configuration of the transmitter according to the sixth embodiment.
In the mapping circuits 110-1 to 110-n of this transmitter, for the
shared control information S, a duplicator 110d generates a replica
S' of S. In the selector 110a, S and S' are respectively divided
into S1 and S2, and S'1 and S'2. In MIMO, allocation is performed
so that antennas to transmit S1 and S2 are different from antennas
to transmit S1' and S2'.
[0193] For example, allocation is performed as shown in FIG. 11B.
In this case, in order that the shared control information received
in the receiver has the same allocation, allocation is performed as
shown in FIG. 11A in non-MIMO.
[0194] Next, in the receiver, by the same processing as in the
first embodiment, the operation is performed up to propagation path
compensation the propagation path compensating circuit 6 of FIG. 2.
The data demodulation circuit 7 combines a plurality of S1 and S2,
and performs demodulation processing regarding as one piece of S1
or S2. As the combining method herein, general selection combining,
equal gain combining and the like may be used.
[0195] FIG. 12 is a diagram showing an example of the data
demodulation circuit 7. In FIG. 12, the data demodulation circuit
is comprised of a divider 7a that divides received signals S1, S2,
S'1 and S'2 into S1 and S2, and S'1 and S'2, a combiner 7b that
combines signals S1 and S'1, and S2 and S'2 divided in the divider
7a and that calculates combined values Sg1 and Sg2, a demodulator
7c that demodulates the combined value combined in the combiner 7b,
and a decoder 7d that decodes the demodulated signal and that
outputs data of the shared control information. As described above,
the receiver is provided with the divider 7a and combiner 7b, and
is thereby capable of performing diversity reception.
[0196] As in the foregoing, by generating replicas of the shared
control information and controlling the replicas to be transmitted
from different antennas in MIMO, the receiver performs combining
processing, and is capable of obtaining the spatial diversity
effect. Naturally, also in non-MIMO, transmitting the replicas
enables the frequency diversity effect to be obtained.
[0197] Further, to enhance the frequency diversity effect in
non-MIMO, it is possible to allocate signals to be apart from
respective replicated signals as shown in FIGS. 13A and 13B.
[0198] (Explanation of an Antenna to Select)
[0199] In the first and fifth embodiments as described above, the
processing is performed so that in a sub-block in which a single
antenna transmits a pilot signal in a MIMO-block, the other
antennas do not transmit pilot signals. However, by regarding pilot
signals of a plurality of sub-blocks transmitted from an antenna as
being one unit, and performing different coding processing on a
unit basis of each antenna, it is possible to make the pilot
signals for each antenna to be orthogonal to one another. This
means that pilot signals in the same sub-block transmitted from a
plurality of antennas can be separated as a pilot signal for each
antenna in the receiving apparatus.
[0200] For example, in the case of two transmission antennas, using
two sub-blocks used in transmission of pilot signals as one unit,
in MIMO, (1,1) are transmitted in the two sub-blocks from the first
antenna, and (1,-1) is transmitted from the second antenna.
Meanwhile, the terminal obtains R1+R2 in obtaining pilot signals
transmitted from the first antenna, for one unit (R1, R2) of
received pilot signals, and is thereby capable of canceling pilot
signals transmitted from the second antenna.
[0201] Similarly, in obtaining pilot signals transmitted from the
second antenna, the terminal obtains R1-R2 and is thereby capable
of canceling pilot signals transmitted from the first antenna.
[0202] In the aforementioned case, assuming changes in amplitude
and phase of a pilot signal of each antenna and a pilot signal in
non-MIMO in one sub-block as a complex R, by complex-multiplying
the shared control information to undergo propagation path
estimation using the pilot signal in the sub-block by R to
transmit, the terminal is capable of performing the demodulation
processing of the first and fifth embodiments.
[0203] For example, assuming two transmission antennas, FIGS. 14A
to 14C show C(1,1) to C(4,1) extracted as part of block
configurations for each transmission antenna in the case that the
block structure is as shown in FIG. 17A. FIG. 14A shows allocation
of pilot signals P and shared control information S1 and S2 in
non-MIMO. Herein, for allocation of the shared control information
S1 and S2 in MIMO, each of the information S1 and S2 is assumed to
be arranged in a configuration of a transmission antenna of a pilot
signal nearest on the low frequency side in the same sub-block as
in the fifth embodiment.
[0204] FIG. 14B shows allocation where the first antenna transmits
(P,P) and the second transmission antenna transmits (P,-P) so that
pilot signals are orthogonal for each transmission antenna.
According to the condition as described above, the shared control
information S1 in MIMO is arranged in the configuration of the
transmission antenna of the pilot signal nearest on the low
frequency side, and therefore, is arranged in configurations of
both the first transmission antenna and second transmission
antenna. At this point, there is a case that the pilot signal
changes from a pilot signal in non-MIMO in phase and amplitude.
Herein, a change R in phaseamplitude of C2(3,1) is -1 (R=-1).
[0205] Accordingly, for the shared control information of C2(4,1)
to allocate by selecting C2(3,1) as a pilot signal nearest on the
low frequency side, the processing to complex-multiply R is
performed as shown below.
S2.times.R=-S2
[0206] FIG. 14C illustrates generalized processing of FIG. 14B, and
assuming that a pilot signal changing in phaseamplitude from a
pilot P in non-MIMO is P', and that the change in phaseamplitude is
R, R can be expressed by equation (3).
[Eq. 3]
R=A.times.e.sup.j.theta. (3)
where A is a change in amplitude, .theta. is a change in phase, and
P' can be expressed by complex-multiplication of equation (4).
[Eq. 4]
P'=R.times.P (4)
The shared control information S2' can be expressed by equation
(5), where the information S2' is arranged in a configuration of
the transmission antenna P' by selecting the pilot signal P' as a
pilot signal nearest on the low frequency side.
[Eq. 5]
S2'=R.times.S2 (5)
[0207] Next, to demodulate the above-mentioned signal in the
receiving apparatus, propagation path estimation of C(2,1) is
performed from the change in phaseamplitude between the known pilot
signal P and received C(1,1). Herein, with the effect of noise
neglected, by passing through the propagation path R1, the signal P
transmitted from the first transmission antenna is expressed by
complex-multiplication of P.times.R1. Similarly, by passing through
the propagation path R2, the signal P transmitted from the second
transmission antenna is expressed by complex-multiplication of
P.times.R2.
[0208] The receiving apparatus receives combined two signals,
P.times.R1+P.times.R2. The change in phase amplitude from the known
pilot signal P is:
P(R1+R2)/P=R1+R2.
By passing through the above-mentioned propagation path, the
received signal of transmission signal S1 of C(2,1) is similarly:
S1(R1+R2), and by complex-dividing by the phaseamplitude change
R1+R2 of the pilot signal, S1 can be obtained.
[0209] Next, for the pilot signal of C(3,1), similarly, the
receiving apparatus receives:
P.times.R1+R.times.P.times.R2, and the change in phaseamplitude
is:
P(R1+R.times.R2)/P=R1+R.times.R2.
[0210] The transmission signal of C(4,1) is expressed by:
S2+R.times.S2, and by passing through the above-mentioned
propagation path, this received signal is similarly:
S2(R1+R.times.R2), and by complex-dividing by R1+R.times.R2 that is
the change in phaseamplitude of the above-mentioned pilot signal,
S2 can be obtained.
[0211] Herein, the explanation is made using the fifth embodiment
as an example, but the same processing can be performed also in the
first embodiment.
[0212] (For the Shared Control Information)
[0213] In the first and third to sixth embodiments as described
above, the shared control information undergoes propagation path
estimation and demodulation on a block basis, and also in the case
of transmitting one shared control information in a plurality of
blocks in the frequency direction, when the same mapping means is
used in the plurality of blocks, it is possible to perform
propagation path estimation and demodulation of the shared control
information irrespective of MIMO or not.
* * * * *