Method and apparatus for transmitting signals using codebooks in a wireless communication system that supports multiple antennas

摘要

The present invention relates to a wireless communication system, and more particularly, to a method and apparatus for transmitting signals using codebooks in a wireless communication system that supports multiple antennas. A method in which a base station transmits downlink signals according to one embodiment of the present invention comprises the following steps: receiving a first precoding matrix indicator (PMI) and a second precoding matrix indicator from a terminal; determining a first matrix (W1) from a first codebook including precoding matrixes indicated by the first PMI, determining a second matrix (W2) from a second codebook, including precoding matrices indicated by the second PMI, and determining a precoding matrix (W) based on the first matrix (W1) and second matrix (W2); performing precoding on one or more layers, to which the downlink signals are mapped, using the determined precoding matrix (W); and transmitting the precoded signals to the terminal. Each of the precoding matrices included in the first codebook is a block diagonal matrix, and one block has, as compared to the other block, a form multiplied by a predetermined phase value.

主权项

1. A method of transmitting a downlink signal, which is transmitted by a base station, comprising the steps of:
receiving a 1st PMI (precoding matrix indicator) and a 2nd PMI from a user equipment; determining a 1st matrix (W1) from a 1st codebook including precoding matrixes indicated by the 1st PMI, determining a 2nd matrix (W2) from a 2nd codebook including precoding matrixes indicated by the 2nd PMI, determining a precoding matrix (W) based on the 1st matrix (W1) and the 2nd matrix (W2); performing a precoding on at least one layer having the downlink signal mapped thereto using the determined precoding matrix (W); and transmitting the precoded signal to the user equipment, wherein each of the precoding matrixes included in the 1st code book is configured with a block diagonal matrix, the block diagonal matrix including a first block and a second block on a diagonal, wherein the second block is multiplied by a prescribed phase value while the first block is not multiplied by the prescribed phase value, and wherein the 1st matrix (W1) is configured as a following formula:w1(n)=[X(n)00α(n)⁢X(n)], wherein the X(n) and the α(n)X(n) respectively correspond to the first and the second blocks of the block diagonal matrix, and wherein the α(n) corresponds to the prescribed phase value.