Massive multiple-input multiple-output (MIMO) and reconfigurable intelligent surface (RIS) are two promising technologies for 5G-and-beyond wireless networks, capable of providing large array gain and multiuser spatial multiplexing. Without requiring additional frequency bands, those technologies offer significant improvements in both spectral and energy efficiency by simultaneously serving many users. The performance analysis of an RIS-assisted Massive MIMO system as a function of the channel statistics relies heavily on fundamental properties including favorable propagation, channel hardening, and rank deficiency. The coexistence of both direct and indirect links results in aggregated channels, whose properties are the main concerns of this lecture note. For practical systems with a finite number of antennas and scattering elements of the RIS, we evaluate the corresponding deterministic metrics with Rayleigh fading channels as a typical example.
翻译:大量投入的多输出(MIMO)和可重新配置的智能表面(RIS)是5G和超越的无线网络的两种有希望的技术,能够提供大型阵列增益和多用户空间多倍化。这些技术不要求增加频带,通过同时为许多用户服务,在光谱和能源效率两方面都大有改进。作为频道统计的一个功能,对RIS辅助的大规模MIMO系统的性能分析严重依赖基本特性,包括有利的传播、频道硬化和等级缺陷。直接和间接连接在集成的渠道中的结果并存,其特性是本演讲说明的主要关切。对于带有有限天线和RIS散射元素的实用系统,我们用Rayleigh流流道评估相应的确定性指标作为典型的例子。