Despite the advantage of power efficiency and spectral efficiency, spatial modulation (SM) technology makes communication systems sensitive to the transmission impairment. This paper analytically investigates the performance of SM multiple-input multiple-output (MIMO) systems where power amplifier (PA) shows clear nonlinearity. Firstly, the system model is presented with nonlinear distortion included. Secondly, the system symbol error rate (SER) is newly derived to a polynomial based function of system parameters. Thirdly, the asymptotical behaviour of SER is analysed, and it is found that SER in nonlinear SM-MIMO systems has a lower limit. Finally, the analytical expressions of SER lower bond are presented. The analysis methodology and derived findings can be a useful reference for the designers of SM-MIMO systems.

尽管具有功率效率和频谱效率的优势，但是空间调制（SM）技术使通信系统对传输损害敏感。本文分析研究了功率放大器（PA）表现出明显非线性的SM多输入多输出（MIMO）系统的性能。首先，给出了包含非线性失真的系统模型。其次，将系统符号错误率（SER）重新推导为基于多项式的系统参数函数。第三，分析了SER的渐近行为，发现在非线性SM-MIMO系统中SER有一个下限。最后，给出了SER低键的解析表达式。分析方法和得出的发现可以为SM-MIMO系统的设计者提供有用的参考。