Patent ID: 8705612
Filing Date: 2014-04-22
Classification: H04L

Abstract:
1. A method for generating a downlink signal at a base station in a downlink multiple input multiple output (MIMO) system, the method comprising: mapping, by the base station, two codewords to a plurality of layers including layer performing, by the base station, layer permutation within a codeword among the two codewords shown in Table 1 according to the following Table 2 when the codeword is for retransmission, where k is a subcarrier index, I is an orthogonal frequency division multiplexing (OFDM) symbol index, θ i (i=1, 2, 3) is a phase shift angle and DFT N*N is an N*N discrete Fourier transform (DFT) matrix where N is an integer, wherein 2-layers, 3-layers, and 4-layers in Table 2 represent a total number of layers included within the codeword; and generating, by the base station, an OFDM symbol using the permutated layers.