低检测复杂度的空码索引调制方案

Space-Code Index Modulation Scheme with Low Detection Complexity

为了提高多输入多输出(MIMO)系统中索引调制方案的频谱效率,文章将空间调制(SM)和码索引调制(CIM)相结合,并利用并行传输的思想,使每个时隙的传输信息比特由两个调制符号、两个天线索引和两个伪随机(PN)码索引进行传输。此外,文章所提方案还利用天线选择技术和正交振幅调制符号的旋转对称特性,分别提高了系统的误码率(BER)性能,降低了接收机的检测复杂度。仿真结果表明,文章所提方案的BER性能明显优于其他几种索引调制方案,并且与最优的最大似然(ML)检测算法相比,文章提出的低复杂度ML检测算法具有与其相同的BER性能。

In order to improve the spectral efficiency of the index modulation scheme in Multiple Input Multiple Output(MIMO)systems,this paper combines Spatial Modulation(SM)with Code Index Modulation(CIM)and uses the idea of parallel transmission to convey the transmission information bits by two modulation symbols,two antenna indexes,and two Pseudo Noise(PN)code indexes in each time slot.In addition,the proposed scheme also uses the antenna selection technique and the rotational symmetry characteristics of the quadrature amplitude modulation symbols to improve the Bit Error Rate(BER)performance of the system and reduce the detection complexity of the receiver,respectively.The simulation results show that the BER performance of the proposed scheme is obviously better than other index modulation schemes,and the low complexity Maximum Likelihood(ML)detection algorithm proposed in this paper has the same BER performance compared with the optimal ML detection algorithm.