基于解析误比特率的空间调制系统配置优化

摘要

在推导空间调制( Spatial Modulation,SM)系统解析误比特率( Bit Error Rate,BER)上界的基础上,通过合理配置天线数量和调制阶数等系统参数,优化SM系统误比特性能.采用矩生成函数法给出SM系统解析BER上界,将BER解析解上界与蒙特卡洛仿真对比,验证解析BER上界的紧致性.基于紧致的解析BER上界,优化天线数量和调制阶数等SM系统主要配置参数,提升SM系统误比特性能.实验结果表明,采用QPSK信号映射配置SM系统能够获取最优的误比特性能,同时在信号调制阶数确定的前提下,通过在发射端增加发射天线数量能够在几乎不牺牲SM系统误比特性能且不增加射频链的前提下有效提升系统传输速率.%Based on the analytical Bit Error Rate ( BER) upper bound of Spatial Modulation ( SM) systems,the optimal configuration of SM by allocating properly of the information bits onto spatial and signal constellation diagrams is investigated.The analytical BER upper bound of SM systems is derived by employing the moment generating function method.The tightness of the upper bound is verified by a comparison to Monte-Carlo simulations.The antenna number and modulation order of SM systems are optimized based on the upper bound of analytical BER.It is shown that,the Quadrature Phase Shift Keying ( QPSK ) signal mapping is the optimal constellation in SM systems in terms of BER.Also,a SM system with a given signal constellation can increase the transmission rate without sacrificing BER performance and adding Radio Frequency ( RF) chains by increasing the number of transmit antennas.