Patent ID: 7839944

Claim:
A method of transmitting data to a receiver by a transmitter using a phase shift-based precoding in a multiple antenna system using a plurality of subcarriers, the method comprising: determining a precoding matrix (P) from a first codebook as a first part of a phase shift-based precoding matrix; determining a diagonal matrix (D) to provide different phase angles to each of the multiple antennas as a second part of the phase shift-based precoding matrix; selecting a unitary matrix (U) as a third part of the phase shift-based precoding matrix; and performing precoding to symbols associated with subcarriers based on the phase shift-based precoding matrix generated as P*D*U which is expressed as: ( ℙ N t × R ) ⁢ ( ⅇ j ⁢ ⁢ θ 1 ⁢ k 0 … 0 0 ⅇ j ⁢ ⁢ θ 2 ⁢ k … 0 ⋮ ⋮ ⋱ ⋮ 0 0 … ⅇ j ⁢ ⁢ θ R ⁢ k ) ⁢ ( 𝕌 R × R ) , wherein (P N t ×R ) denotes the precoding matrix (P), N t denotes a number of transmit antenna, (U R×R ) denotes the unitary matrix (U), k denotes an index associated with the subcarriers, θ i (i=1, . . . , R) denotes a phase angle, and R denotes a spatial multiplexing rate, wherein the phase angles θ i (i=1, . . . , R) of the diagonal matrix (D) are linearly increased according to the index of ‘i’.