中文摘要：

速率为2的空时分组码（R2-STBC）能达到全速率全分集,然而其译码复杂度与调制阶数的平方成正比。为了降低译码复杂度,提出了一种基于相位旋转的、速率为2的空时分组码（PR-R2-STBC）,发送端根据反馈信息将部分发送信号旋转一定的角度,实现了信号在传输过程中两两正交,从而使得其译码复杂度与调制阶数成正比。仿真结果显示,与R2-STBC相比,该编码仅需反馈7 bit就极大地降低了译码复杂度。

英文摘要：

The full rate and full diversity could be achieved by Rate-2 space-time block code,whereas the decoding complexity is proportional to the square of the modulation order.A rate-2 space time block code with phase rotation is proposed in order to reduce the decoding complexity.Part of the transmitted signals is rotated by a certain angle,and the pairwise orthogonal between the transmitted signals is realized in the proposed scheme,so that the decoding complexity is proportional to the modulation order.Simulation results demonstrate the decoding complexity is reduced greatly by proposed code only with 7 bit feedback.