Patent ID: 7970073

Claim:
A transmitter for a multi-user multi-antenna communication system, the transmitter comprising: a Spatial Multiplexing (SM) transmit (TX) filter unit for computing a TX filter for each user receiver, selecting a codebook having a highest correlation to each computed TX filter among prestored codebooks, and outputting an index of each selected codebook; and a plurality of antennas for transmitting the index of each selected codebook to each respective user receiver; wherein the codebook is selected using the following: i = arg ⁢ ⁢ max i ⁢ ⁢ # ⁢ jC ⁢  U j * ⁢ W k  where U j denotes a j th codebook among a total of C codebooks, W k denotes an actual receive (RX) filter of the k th user receiver, and an index i of a codebook with a highest correlation between U j and W k is selected.