Method and apparatus for determining precoding matrix

摘要

Embodiments of the present disclosure disclose a method and an apparatus for determining a precoding matrix, which relate to the field of communications technologies and may improve throughput of a MIMO system and optimize overall system performance, including: determining a rank constraint of a jth transmitting end, where j=1, 2, . . . , K, and K is the total number of transmitting ends in a MIMO system; iteratively calculating an optimal precoding matrix of the jth transmitting end according to a channel matrix from the jth transmitting end to a jth receiving end, an autocorrelation matrix of interference and noise of the jth receiving end, and the rank constraint of the jth transmitting end, where the optimal precoding matrix maximizes channel capacity of a link from the jth transmitting end to the jth receiving end under a circumstance that precoding matrices of other transmitting ends do not change.

主权项

1. A method for determining a precoding matrix, comprising:
determining, by a communication device, a rank constraint of a jth transmitting end; and calculating, by the communication device, iteratively an optimal precoding matrix of the jth transmitting end according to a channel matrix from the jth transmitting end to a jth receiving end, an autocorrelation matrix of interference and noise of the jth receiving end, and the rank constraint of the jth transmitting end, wherein the optimal precoding matrix maximizes channel capacity of a link from the jth transmitting end to the jth receiving end under a circumstance that precoding matrices of other transmitting ends do not change, j=1, 2, . . . , K, and K is a total number of the transmitting ends or receiving ends in a Multiple-Input Multiple-Output (MIMO) system; wherein the calculating iteratively the optimal precoding matrix of the jth transmitting end according to the channel matrix from the jth transmitting end to the jth receiving end, the autocorrelation matrix of interference and noise of the jth receiving end and the rank constraint of the jth transmitting end comprises: calculating iteratively a preset optimization problem; and obtaining a corresponding optimal solution when the preset optimization problem converges to a Nash equilibrium point during iterative calculation, wherein the optimal solution is the optimal precoding matrix of the jth transmitting end, wherein the preset optimization problem ismaxQj⁢log⁢⁢det⁡(I+HjjH⁢Rj-1⁢Hjj⁢Qj)⁢subject⁢⁢to⁢Qj≥0⁢Rank⁡(Qj)≤rj⁢Trace⁡(Qj)≤Pj,  wherein log det(I+HjjHRj−1HjjQj) denotes channel capacity of a link between the jth transmitting end and the jth receiving end, I denotes a unit matrix, Hjj denotes a channel matrix from the jth transmitting end to the jth receiving end, Rj denotes an autocorrelation matrix of interference and noise of the jth receiving end after the precoding matrix is iteratively updated last time, Qj=FjFjH, j=1, 2, . . . , K, K is the total number of the transmitting ends, Qj is an autocorrelation matrix of a transmitting signal of the jth transmitting end, Fj is a precoding matrix of the jth transmitting end, rj is a rank constraint of the jth transmitting end, Rank(Qj) denotes a rank of Qj, Pj is a transmitting power constraint of the jth transmitting end, and Trace (Qj) denotes a trace of Qj.