Patent ID: 7508880

Claim:
A transmitter with three transmit antennas in a communication system using a space-time-frequency block coding scheme, the transmitter comprising: a pre-coder for pre-coding a symbol vector of an input symbol sequence by multiplying the symbol vector by e jθ , θ being a phase rotation angle, reconstructing the symbol vector multiplied with e jθ and outputting pre-coded symbols c 1 , c 2 , c 3 , and c 4 , given as, c 1 =x 1 +jy 3 c 2 =x 2 +jy 4 c 3 =x 3 +jy 1 c 4 =x 4 +jy 2 where c k represents a k th pre-coded symbol, x k represents a real term of k th symbol within the symbol vector multiplied with e jθ , and jy k represents an imaginary term of k th symbol within the symbol vector multiplied with e jθ ; and a space-time-frequency block code (STFBC) mapper for selecting an STFBC using a permutation matrix in which the following matrices A, B and C are arranged in a predetermined order, mapping the pre-coded symbols to the transmit antennas according to the selected STFBC, and transmitting the mapped symbols through the transmit antennas, A = [ s 1 - s 2 * 0 0 s 2 s 1 * s 3 - s 4 * 0 0 s 4 s 3 * ] B = [ s 1 - s 2 * s 3 - s 4 * s 2 s 1 * 0 0 0 0 s 4 s 3 * ] C = [ s 1 - s 2 * 0 0 0 0 s 3 - s 4 * s 2 s 1 * s 4 s 3 * ] where a row represents sysmbols for a corresponding antenna and a column represents symbols mapped with a subcarrier.