Efficient MIMO precoding feedback scheme

摘要

Methods and apparatus for efficiently feeding back preceding information in a multiple input multiple output (MIMO) system. A codebook including a plurality of codebook entries is constructed. A plurality of subsets of codebook entries are defined for the codebook. Each subset includes a plurality of codebook entries. A subset of codebook entries is selected for precoding data in dependence upon a channel condition, and a codebook entry is selected from the subset. Then, a subset index corresponding to the selected subset, and a codebook entry index corresponding to the selected codebook entry within the selected subset, is transmitted as feedback information.

主权项

1. A method for communication, the method comprising:
constructing a codebook comprising a plurality of codebook entries; defining a plurality of subsets of codebook entries from the codebook, with each subset comprising a plurality of codebook entries, each codebook entry comprising a plurality of precoding matrices for respective corresponding transmission ranks; selecting a subset for precoding data in dependence upon a channel condition; selecting a codebook entry from the subset for precoding data; and transmitting, via at least one antenna, a subset index corresponding to the selected subset, and a codebook entry index corresponding to the selected codebook entry within the selected subset.