Performance of a Double RIS Communication System Aided by Partially Active Elements

Reconfigurable intelligent surface (RIS) has emerged as a promising technology to enhance the spectral efficiency of wireless communication systems. However, if there are many obstacles between RIS and users, single may not provide sufficient performance. For this reason, double RIS-aided system is proposed in paper. also problem: signal attenuated three times due channels created by RIS. To overcome these attenuations, an active An almost same conventional RIS, except for included amplifier. Comprehensively, overcomes various attenuations. In paper, applied second reduce power consumption elements, partially applied. optimize sum covariance matrix found using related each right singular vector exploited value decomposition matrix. Then, checked determine which element element. Simulation results show that better rate performance compared system. Although it lower with fully will be more attractive future because much energy efficiency.