Adaptive Rotation Based Full-Diversity Full-Rate Scheme with Channel State Information

Open-loop full-diversity full-rate (FDFR) code can achieve both high data rate and good reliability at the expense of significantly increased decoding complexity. To mitigate the decoding complexity, low-complexity FDFR code was designed for closed-loop system, combining the preceding and constellation rotation with channel state information (CSI) at the transmitter. Since conventional closed loop FDFR encoding procedure is similar to that of open loop FDFR code, however, it suffers from latency problem due to multiple-symbol-periods encoding and decoding process. Also, the rotation matrix is fixed irrespective of temporal channel response. In this paper, we propose simple FDFR scheme which performs single-symbol- period encoding and decoding procedure. Moreover, we improve error performance of closed-loop FDFR code by exploiting a adaptive rotation matrix corresponding to temporal channel state, especially the singular values of channel. The adaptive rotation matrix construction aims at maximizing the minimum Euclidean distance among received signals. Simulation results support the validity of the proposed FDFR scheme.