Closed-Loop Space Time Block Coding for High Data Rate With Angle Feedback
Transmit diversity schemes with multiple streams obtain reliable transmission but suffer from interference when decoding multiple streams simultaneously. In this paper, the authors present closed-loop space-time block codes for multiple streams with limited channel information in order to ease suppressing interference at a receiving station. The proposed scheme includes constellation rotation in Alamouti coding pairs by feedback angle information. The sub-optimum solution for feedback angle is found to maximize the output Signal-to-Noise Ratio (SNR). Simulation results show the proposed scheme with only a few bits feedback achieves nearly full diversity gain with reduced interference.