Patent ID: 8351535

Claim:
A method of data transmission from a transmitter of a wireless communication system which uses multiple antennas, the method comprising: receiving identification information of a precoding matrix from a receiver, the precoding matrix being selected from a codebook generated using a plurality of first matrices generated by multiplying a discrete fourier transform (DFT) matrix by each of a plurality of phase shift matrices; precoding data to be transmitted, by using a precoding matrix indicated by the identification information; and transmitting the precoded data to the receiver by using the multiple antennas, wherein each of the plurality of phase shift matrices is a diagonal matrix, and when N is the number of the plurality of phase shift matrices and i is an integer greater than or equal to 0 and less than N, (k,k) element of the ith phase shift matrix of the plurality of phase shift matrices is ⅇ j ⁡ ( k - 1 ) ⁢ ϕ i , ϕ i = π * i 2 ⁢ N .