Patent ID: 8467475

Claim:
A method of transmission implemented in a wireless communication system using precoding, comprising: precoding data using a precoding matrix based on a codebook which has entries in the following form A ⁡ ( v 1 , v 2 , v 3 , … ) = [ v 1 , H ⁢ ⁢ H ⁡ ( v 1 - e 1 M ) ⁡ [ 0 v 2 ] , H ⁢ ⁢ H ⁡ ( v 1 - e 1 M ) ⁡ [ 0 H ⁢ ⁢ H ⁡ ( v 2 - e 1 M - 1 ) ⁡ [ 0 v 3 ] ] ] , … where a transmitter has M antennas, e 1 N =[1,0, . . . ,0] T εC N (N=M, M−1, . . .), C N being N-dimensional complex space, V a denotes a column vector, and HH(v k −e 1 l ) is a rotation matrix that transforms vector v k to the unit vector e 1 l .