采用二重天线激活矩阵的差分空间调制算法

Differential Spatial Modulation with Twofold Antennas Selection

针对传统差分空间调制算法(DSM)不能获取发射分集的问题,提出了一种采用二重天线激活矩阵的差分空间调制算法,简称TA-DSM算法。该算法对天线激活矩阵集合中的元素进行了两次独立选择,得到两个天线激活矩阵。再将这两个矩阵分别和P个Alamouti矩阵的第1行和第2行相乘,以此获得TA-DSM发送信号。由于该算法使用了两个天线激活矩阵,所以与现有的空时编码DSM(STBC-DSM)相比,TA-DSM可以传递更多的比特数,从而获得更高的频谱效率。因此,在频谱效率相同的情况下,TA-DSM可以拥有更好的误码性能。同时,文中系统地提出了构造天线激活矩阵的简单方法,使TA-DSM可以获得二阶发射分集。最后,针对TA-DSM提出了低复杂度解码算法。仿真结果表明,TA-DSM方案比现有的STBC-DSM具有更好的误码性能,当频谱效率为1.33 b/(s·Hz)时,相比STBC-DSM,TA-DSM可以获得约4 dB的性能增益;当频谱效率为2 b/(s·Hz)时,TA-DSM可以获得约1.5 dB的性能增益。

A new multiple-input multiple-output(MIMO)transmission scheme termed differential spatial modulation with twofold antennas selection(TA-DSM)is proposed to solve the problem that the traditional differential spatial modulation(DSM)cannot achieve transmit diversity.In this scheme,one set of antenna activation matrices(AMs)is employed,from which a pair of AMs are respectively selected.Then the two selected AMs are combined with the first row and the second row of P Alamouti matrices,respectively,to generate the TA-DSM signal.Due to employing an extra AM,the proposed TA-DSM scheme delivers more bits,resulting in higher spectral efficiency than the existing typical DSM schemes,for example,the STBC-DSM scheme.In other words,TA-DSM can achieve better bit error performance than the existing typical DSM schemes when they are in the same spectral efficiency.Also,a simple and systematic method to construct the set of AMs and modulation matrices is presented,which guarantees that the TA-DSM scheme can achieve the second order transmit diversity.Furthermore,a low-complexity detector is introduced and the simulation shows the performance improvement of the proposed TA-DSM scheme.Compared with STBC-DSM scheme,the TA-DSM scheme achieves about 4 dB performance gain with a spectral efficiency of 1.33 b/(s·Hz)and about 1.5 dB gain with a spectral efficiency of 2 b/(s·Hz).