Method for obtaining precoding matrix and apparatus
A method for obtaining a precoding matrix includes obtaining a joint precoding matrix of M terminals based on statistical autocorrelation matrices respectively corresponding to N terminals in the M terminals, where M and N are positive integers, M≥2, and 1≤N≤M. The method further includes outputting information that is useable to indicate the joint precoding matrix. The N terminals include a terminal n j , wherein a statistical autocorrelation matrix R n j corresponding to the terminal n j is obtainable by filtering an autocorrelation matrix R n j corresponding to the terminal n j in a frequency domain or a time domain, j is a positive integer, 1≤j≤N, and the autocorrelation matrix R n j corresponding to the terminal n j is obtainable based on a channel estimation result H n j corresponding to the terminal n j .
1 . A method, wherein the method comprises:
obtaining, by a network device, a joint precoding matrix of M terminals based on statistical autocorrelation matrices respectively corresponding to N terminals in the M terminals, where M and N are positive integers, M≥2, and 1≤N≤M;
outputting, by the network device, information that is useable to indicate the joint precoding matrix; and
generating, by the network device, precoding signals based on the joint precoding matrix, and transmitting data based on the precoding signals;
wherein the N terminals comprise a terminal n j , wherein a statistical autocorrelation matrix R n j corresponding to the terminal n j is obtainable by filtering an autocorrelation matrix R n j corresponding to the terminal n j in a frequency domain or a time domain, j is a positive integer, 1≤j≤N, and the autocorrelation matrix R n j corresponding to the terminal n j is obtainable based on a channel estimation result H n j corresponding to the terminal n j .
2 . The method according to claim 1 , wherein the statistical autocorrelation matrix R n j comprises T main diagonal blocks and a zero element other than the T main diagonal blocks, and T is an integer greater than or equal to 2.
3 . The method according to claim 1 , wherein
the M terminals comprise P terminals, the P terminals comprise a terminal p x , the terminal p x corresponds to a coefficient matrix B p x , where B p x is related to a channel estimation result corresponding to each of the P terminals, where P and x are positive integers, 1≤P≤M, and 1≤x≤P; and
the N terminals comprise Q terminals in the P terminals, the Q terminals comprise a terminal q y , and
obtaining the joint precoding matrix of the M terminals based on the statistical autocorrelation matrices respectively corresponding to the N terminals in the M terminals comprises:
obtaining the joint precoding matrix based on corrected statistical autocorrelation matrices corresponding to the Q terminals and a statistical autocorrelation matrix of a terminal in the N terminals and being other than the Q terminals, wherein
a corrected statistical autocorrelation matrix
R
q
y
′
corresponding to the terminal q y is obtainable by correcting a statistical autocorrelation matrix R q y corresponding to the terminal q y based on a coefficient matrix Bay corresponding to the terminal q y , where Q and y are positive integers, 1≤Q≤P, 1≤Q≤N, and 1≤y≤Q.
4 . The method according to claim 3 , wherein the obtaining the joint precoding matrix based on the corrected statistical autocorrelation matrices corresponding to the Q terminals and the statistical autocorrelation matrix of the terminal in the N terminals and being other than the Q terminals comprises:
obtaining the joint precoding matrix based on the corrected channel estimation result
H
p
x
′
corresponding to the terminal p x , the corrected statistical autocorrelation matrices corresponding to the Q terminals, and the statistical autocorrelation matrix of the terminal in the N terminals and being other than the Q terminals, wherein
the corrected channel estimation result
H
p
x
′
corresponding to the terminal p x is obtainable by correcting a channel estimation result H p x corresponding to the terminal p x based on a coefficient matrix B p x corresponding to the terminal p x .
5 . The method according to claim 1 , wherein the M terminals comprise P terminals, the P terminals comprise a terminal p x , the terminal p x corresponds to a coefficient matrix B p x , and B p x is related to a channel estimation result corresponding to each of the P terminals, P and x are positive integers, 1≤P≤M, and 1≤x≤P; and
the obtaining the joint precoding matrix of the M terminals based on the statistical autocorrelation matrices respectively corresponding to the N terminals comprises:
obtaining the joint precoding matrix based on the corrected channel estimation result
H
p
x
′
corresponding to the terminal p x and the statistical autocorrelation matrices respectively corresponding to the N terminals, wherein
the corrected channel estimation result
H
p
x
′
corresponding to the terminal p x is obtainable by correcting a channel estimation result H p x corresponding to the terminal p x based on the coefficient matrix B p x corresponding to the terminal p x .
6 . The method according to claim 1 , wherein the M terminals comprise the N terminals and a first terminal, where a precoding matrix that is in the joint precoding matrix and that corresponds to the first terminal is related to the statistical autocorrelation matrices respectively corresponding to the N terminals.
7 . The method according to claim 1 , wherein N≥2, the N terminals comprise a first terminal, and a precoding matrix that is in the joint precoding matrix and that corresponds to the first terminal is related to statistical autocorrelation matrices respectively corresponding to N−1 terminals in the N terminals and being other than the first terminal.
8 . The method according to claim 7 , wherein the precoding matrix that is in the joint precoding matrix and that corresponds to the first terminal is further related to another statistical autocorrelation matrix corresponding to the first terminal.
9 . The method according to claim 1 , wherein the outputting, by the network device, the information that is useable to indicate the joint precoding matrix comprises: outputting information that is useable to indicate a compressed matrix, wherein the compressed matrix corresponds to the joint precoding matrix.
10 . The method according to claim 1 , wherein the channel estimation result H n j corresponding to the terminal n j is obtainable by measuring an uplink reference signal or is obtainable based on information that is fed back by another terminal and that indicates an initial precoding matrix.
11 . A communication apparatus, wherein the communication apparatus comprises:
a processor configured to obtain a joint precoding matrix of M terminals based on statistical autocorrelation matrices respectively corresponding to N terminals in the M terminals, where M and N are positive integers, M≥2, and 1≤N≤M; and
an interface configured to output information that is useable to indicate the joint precoding matrix, to generate precoding signals based on the joint precoding matrix, and to transmit data based on the precoding signals,
wherein the N terminals comprise a terminal n j , wherein a statistical autocorrelation matrix R n j corresponding to the terminal n j is obtainable by filtering an autocorrelation matrix R n j corresponding to the terminal n j in a frequency domain or a time domain, j is a positive integer, 1≤j≤N, and the autocorrelation matrix R n j corresponding to the terminal n j is obtainable based on a channel estimation result H n j corresponding to the terminal n j .
12 . The communication apparatus according to claim 11 , wherein the statistical autocorrelation matrix R n j comprises T main diagonal blocks and a zero element other than the T main diagonal blocks, and T is an integer greater than or equal to 2.
13 . The communication apparatus according to claim 11 , wherein
the M terminals comprise P terminals, the P terminals comprise a terminal p x , the terminal p x corresponds to a coefficient matrix B p x , where B p x is related to a channel estimation result corresponding to each of the P terminals, where P and x are positive integers, 1≤P≤M, and 1≤x≤P; and
the N terminals comprise Q terminals in the P terminals, the Q terminals comprise a terminal q y , and
the processor configured to obtain the joint precoding matrix of the M terminals based on the statistical autocorrelation matrices respectively corresponding to the N terminals in the M terminals comprises:
the processor configured to obtain the joint precoding matrix based on corrected statistical autocorrelation matrices corresponding to the Q terminals and a statistical autocorrelation matrix of a terminal in the N terminals and being other than the Q terminals, wherein
a corrected statistical autocorrelation matrix R′ q y corresponding to the terminal q y is obtainable by correcting a statistical autocorrelation matrix R q y corresponding to the terminal q y based on a coefficient matrix B q y corresponding to the terminal q y , where Q and y are positive integers, 1≤Q≤P, 1≤Q≤N, and 1≤y≤Q.
14 . The communication apparatus according to claim 13 , wherein the processor configured to obtain the joint precoding matrix based on the corrected statistical autocorrelation matrices corresponding to the Q terminals and the statistical autocorrelation matrix of the terminal in the N terminals and being other than the Q terminals comprises:
the processor configured to obtain the joint precoding matrix based on the corrected channel estimation result
H
p
x
′
corresponding to the terminal p x , the corrected statistical autocorrelation matrices corresponding to the Q terminals, and the statistical autocorrelation matrix of the terminal in the N terminals and being other than the Q terminals, wherein
the corrected channel estimation result
H
p
x
′
corresponding to the terminal p x is obtainable by correcting a channel estimation result H p x corresponding to the terminal p x based on the coefficient matrix B p x corresponding to the terminal p x .
15 . The communication apparatus according to claim 11 , wherein the M terminals comprise P terminals, the P terminals comprise a terminal p x , the terminal p x corresponds to a coefficient matrix B p x , and B p x is related to a channel estimation result corresponding to each of the P terminals, P and x are positive integers, 1≤P≤M, and 1≤x≤P; and
the processor configured to obtain the joint precoding matrix of the M terminals based on the statistical autocorrelation matrices respectively corresponding to the N terminals in the M terminals comprises:
the processor configured to obtain the joint precoding matrix based on a corrected channel estimation result
H
p
x
′
corresponding to the terminal p x and the statistical autocorrelation matrices respectively corresponding to the N terminals, wherein
the corrected channel estimation result
H
p
x
′
corresponding to the terminal p x is obtainable by correcting a channel estimation result H p x corresponding to the terminal p x based on the coefficient matrix B p x corresponding to the terminal p x .
16 . The communication apparatus according to claim 11 , wherein the M terminals comprise the N terminals and a first terminal, where a precoding matrix that is in the joint precoding matrix and that corresponds to the first terminal is related to the statistical autocorrelation matrices of the N terminals.
17 . The communication apparatus according to claim 11 , wherein N>1, the N terminals comprise a first terminal, and a precoding matrix that is in the joint precoding matrix and that corresponds to the first terminal is related to statistical autocorrelation matrices of N−1 terminals, in the N terminals and being other than the first terminal.
18 . The communication apparatus according to claim 17 , wherein the precoding matrix that is in the joint precoding matrix and that corresponds to the first terminal is further related to a statistical autocorrelation matrix of the first terminal.
19 . The communication apparatus according to claim 11 , wherein the interface is further configured to:
output information that is useable to indicate a compressed matrix, wherein the compressed matrix corresponds to the joint precoding matrix.
20 . The communication apparatus according to claim 11 , wherein the channel estimation result H n j corresponding to the terminal n j is obtainable by measuring an uplink reference signal or is obtainable based on information that is fed back by another terminal and that indicates an initial precoding matrix.