Reconfigurable intelligent surfaces (RISs) have emerged as a promising technique to enhance the system spectral efficiency. This letter 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很有希望的技术,本信调查了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的视线路径。新表达方式是用来描述ECC的上下界特征的。为了揭示更多的系统洞察力,在大型信号对噪音比(SNR)和反射元素数量(REs)的限度内,对ECC系统进行了无症状分析。理论分析表明,RIS的部署能够影响ECC的高分辨率抵消,而ECC可以通过增加RE的数量来改进。