Patent ID: 8451932

Claim:
A transmitter for use with multiple transmit antennas, comprising: a precoder unit configured to precode data for a transmission using a precoding matrix selected from a codebook, wherein the codebook corresponds to the following transmission properties for an uplink transmission: 1) all precoding elements from the precoding matrix have a same magnitude, 2) each precoding element from the precoding matrix is taken from a set of finite values; and a transmit unit configured to transmit the precoded data, wherein the codebook for a rank-1 transmission corresponds to a set of four-element column vectors containing all of the following sixteen vectors: 1 2 ⁡ [ 1 1 1 - 1 ] ⁢ ⁢ 1 2 ⁡ [ 1 1 j j ] ⁢ ⁢ 1 2 ⁡ [ ⁢ 1 ⁢ 1 - 1 ⁢ 1 ] ⁢ ⁢ 1 2 ⁡ [ 1 1 - j - j ] ⁢ 1 2 ⁡ [ 1 j 1 j ] ⁢ ⁢ 1 2 ⁡ [ 1 j j 1 ] ⁢ ⁢ 1 2 ⁡ [ 1 j - 1 - j ] ⁢ ⁢ 1 2 ⁡ [ 1 j - j - 1 ] 1 2 ⁡ [ 1 - 1 1 1 ] ⁢ ⁢ 1 2 ⁡ [ 1 - 1 j - j ] ⁢ ⁢ 1 2 ⁡ [ 1 - 1 - 1 - 1 ] ⁢ ⁢ 1 2 ⁡ [ 1 - 1 - j j ] 1 2 ⁡ [ 1 - j 1 - j ] ⁢ ⁢ 1 2 ⁡ [ 1 - j j - 1 ] ⁢ ⁢ 1 2 ⁡ [ 1 - j - 1 j ] ⁢ ⁢ 1 2 ⁡ [ 1 - j - j 1 ] .