Patent ID: 9553645
Date: 2017-01-24
CPC Classifications: H04B

Claim:
1. A method of transmitting a control signal related to a precoding scheme in a wireless communication system, the method comprising: receiving, by a wireless device from a network device, codebook subset information restricting a possible precoding matrix to be selected by the wireless device from a plurality of possible precoding matrices to a precoding matrix suitable for a channel; selecting, by the wireless device, an Mt×R precoding matrix based on the codebook subset information, wherein the selected Mt×R precoding matrix is to be used for a plurality of antenna ports of the network device; and transmitting, by the wireless device to the network device, information on the selected Mt×R precoding matrix, wherein Mt denotes a number of the plurality of antenna ports and R denotes a number of layers for the restricted precoding matrix, wherein the Mt×R precoding matrix is the restricted precoding matrix and is configured in a form of wherein Q1 denotes a first element matrix for the Mt×R precoding matrix, Q2 denotes a second element matrix for the Mt×R precoding matrix, Q3 denotes a third element matrix for the Mt×R precoding matrix, and Q4 denotes a fourth element matrix for the Mt×R precoding matrix, wherein w1 denotes a weight for the first and second element matrices, and w2 denotes a weight for the third and fourth element matrices, and wherein each of the first, second, third and fourth element matrices has Nt rows, wherein Nt is defined by Nt=Mt/2.