Reconfigurable intelligent surfaces (RISs) have emerged as a promising technique to enhance the system spectral efficiency. This paper investigates the ergodic channel capacity (ECC) of an RIS-aided multiple-input multiple-output channel under the assumption that the transmitter-RIS, RIS-receiver, and transmitter-receiver channels contain deterministic line-of-sight paths. Novel expressions are derived to characterize the upper and lower bounds of the ECC. To unveil more system insights, asymptotic analyses are performed to the system ECC in the limit of large signal-to-noise ratio (SNR) and number of reflecting elements (REs). Theoretical analyses suggest that the RIS's deployment can shape the ECC curve by influencing its high-SNR power offset and the ECC can get improved by increasing the number of REs.
翻译:重新配置的智能表面(RIS)已成为提高系统光谱效率的一种有希望的技术,本文件调查了RIS辅助的多投入多输出输出信道(ECC)的自动信道能力,其假设是,发报机-RIS、RIS-接收器和发报机-接收器频道含有确定性直线路径。新颖的表达方式被用来描述ECC的上下界特征。为了揭示更多的系统洞察力,在大型信号对噪音比率和反射元素数目的限度内,对ECC系统进行了无症状分析。理论分析表明,RIS的部署可以通过影响其高RSR功率的抵消来影响ECC曲线,而ECC可以通过增加RE的数量来改进ECC。