A RIS-assisted wireless communication system in the presence of a direct communication path between the transceiver pair is considered in this paper. The transmitter-RIS and the RIS-receiver channels follow independent Nakagami-m distributions, and the direct channel between the transceiver pair follows a Rayleigh distribution. Considering this system model, the statistics of the composite channel for the RIS-assisted communication system are derived in terms of obtaining novel expressions for the probability density functions for the magnitude and the phase of the communication channel. The correctness of the analytical framework is verified via Monte Carlo simulations, and the effects of the shape parameters of the channels and the number of reflecting elements in the RIS on the randomness of the composite channel are studied via numerical results.

翻译：本文考虑收发对间存在直视通信路径时的RIS辅助无线通信系统。基站-RIS链路与RIS-接收机链路服从独立Nakagami-m分布，收发对间的直视信道服从Rayleigh分布。基于该系统模型，推导了RIS辅助通信系统复合信道的统计特性，获得了通信信道幅度与相位的概率密度函数的新型表达式。通过蒙特卡洛仿真验证了分析框架的正确性，并通过数值结果研究了信道形状参数及RIS反射单元数量对复合信道随机性的影响。