Patent ID: 8861628

Claim:
A layer mapping method for spatial multiplexing in a Multi-Input Multi-Output (MIMO) system, the layer mapping method comprising: mapping symbols associated with each codeword to a corresponding at least one layer according to one of a plurality of mapping combinations; precoding the symbols mapped to the corresponding at least one layer to produce a precoded signal; and transmitting the precoded signals, wherein the maximum number of layers to which the symbols associated with a single codeword are mapped is equivalent to the maximum number of layers employed by the MIMO system divided by the maximum number of codewords, wherein the plurality of mapping combinations comprise only one mapping combination for each combination of a number of codewords and a number of layers, wherein the plurality of mapping combinations comprise first mapping combinations for one codeword and second mapping combinations for multiple codewords, and wherein the first mapping combinations comprise all possible mapping combinations for retransmitting only one codeword among the multiple codewords of the second mapping combinations.