中文摘要：

提出了一种基于匙孔信道的旋转四元素准正交空时分组码（QQOSTBC-CR,Constellation Rotation QuaternionQuasi-Orthogonal Space Time Block Code）,该码可以通过极化天线进行发射和接收,设计出发射天线数为8的QOSTPBC-CR,并对N=8的情况进行成对译码,最后与匙孔信道下传统旋转准正交空时分组码（QOSTBC-CR,Constellation Rotation Quasi-OrthogonalSpace Time Block Code）、准正交空时分组码（QOSTBC,Quasi-Orthogonal Space Time Block Code）以及瑞利信道下QQOSTBC-CR进行了仿真比较。结果表明：对4个发射天线的情况,当BER=10~（-3）时,BPSK和QPSK调制下本文所提QQOSTBC-CR分别比QOSTBC-CR有4.5dB和7dB的增益,分别比瑞利信道下QQOSTBC-CR有-4dB和-3dB的增益。

英文摘要：

A new kind of constellations rotation for quaternion quasi-orthogonal space time block code（QQOSTBC-CR） in keyhole channel is proposed.These codes can transmit and receive through dual-polarized antennas respectively.The QQOSTBC with eight transmit antennas are designed firstly.And pair-wise decoding algorithm is adopted for N=8.Finally,it is compared the QQOSTBC-CR with the QOSTBC-CR（Constellation Rotation Quasi-Orthogonal Space Time Block Code） and QOSTBC（Quasi-Orthogonal Space Time Block Code） in the case of keyhole channel,and with the QQOSTBC-CR in the case of Rayleigh channel.Simulation results show that the new QQOSTBC-CR can provide a gain of 4.5dB/7dB than the QOSTBC-CR at the given BER of 10~（-3） for BPSK/QPSK in the condition of four transmit antennas and keyhole channel,the new QQOSTBC-CR can provide a gain of -4dB/-3dB than the QQOSTBC-CR in the case of Rayleigh channel for BER=10~（-3）.