Performance of transmit diversity scheme with quantized phase-only feedback

Closed-loop (feedback) rate-one channel orthogonalized space-time block codes (CO-STBCs) for 3 and 4 transmit antennas using a single (real) phase feedback are proposed. These codes with ideal feedback achieve full diversity and result in maximum likelihood (ML) decoding with only linear processing at the receiver. In this paper, we study the impact on the error-rate performance when the feedback phase information is quantized. Simulation results suggest that there is a significant SNR advantage even when only one bit is used to represent the phase feedback term. Also, it is found that three bits are sufficient to obtain nearly the ideal feedback performance.