基于旋转和天线选择的Keyhole信道的QSTBC性能分析

Performance of QSTBC in Keyhole channel based on phase rotation and antenna selection

针对匙孔信道下4天线的Jafarkhani码和TBH码的QSTBC码阵系统,对QSTBC的编码结构进行4参数相位旋转,推导出QSTBC-MIMO瞬时输出信噪比表达式,并利用该瞬时输出信噪比作为系统天线选择准则.4参数相位旋转解决多交叉归零问题,使信道矩阵正交化,消除码间串扰,降低最大似然解码复杂度,从而改善系统性能.仿真结果表明:基于相位旋转的QSTBC系统能够获得较传统QSTBC系统更好的性能.采用相位旋转的同时加入天线选择技术的QSTBC系统的性能更好.在相同信噪比条件下,最可行的方法是采用相位旋转加接收端天线选择.

On the QSTBC coding structure 4 parameters of phase rotation,the paper derives a expression of instantaneous output signal-to-noise ratio（SNR） of QSTBC-MIMO with 4 antenna Jafarkhani and TBH codes of QSTBC systems over keyhole channel,and using the instantaneous output signal-to-noise ratio as the antenna selection criteria.4 parameters of phase rotation can solve cross zero problem,while making channel matrix orthogonalization,eliminating inter symbol interference as well as reducing the maximum likelihood decoding complexity,so as to improve the performance of the system.Simulation results show that the phase rotation-based QSTBC system can achieve better performance than that of the traditional QSTBC system.Combing phase rotation with adding antenna selection technology,the QSTBC system has better performance.In the same SNR,the most feasible method is to use phase rotation and the receiver antenna selection.