Patent ID: 8938020
Filing Date: 2015-01-20
Classification: H03M,H04B,H04L

Abstract:
1. A method for transmitting a signal from a transmitter, which supports Nt antennas, to a receiver, the method comprising: selecting a precoding matrix indicated by a combination of a first precoding matrix indicator (PMI) and a second PMI; precoding the signal by using the selected precoding matrix; and transmitting the precoded signal through the Nt antennas, wherein the first PMI indicates one matrix group among N matrix groups (N≧1) including matrices representing channel directions related to the Nt antennas, and the precoding matrix is selected by multiplying the one matrix group indicated by the first PMI by the matrix indicated by the second PMI, and wherein the first PMI is indicated by a third PMI and a fourth PMI, the third PMI indicates one of diagonal matrices of Nt×Nt size, the fourth PMI indicates one of block diagonal matrices of Nt×2 size, the second PMI indicates one of matrices of 2×R size, and R is the number of layers to which the signal is transmitted.