Super Wideband MIMO Systems: Channel Modeling and Performance Analysis

Abstract

This paper develops a physically-consistent channel model for analyzing super wideband (SW) multiple-input-multiple-output (MIMO) communication systems that experience strong mutual coupling (MC). Starting from circuit theory, we derive a generalized MIMO model incorporating MC and physical noise sources, allowing a direct mapping to standard communication models. We develop a correlated Rician channel model with frequency-dependent spatial correlation, frequency correlation, and Rician K-factor, specifically tailored for SW MIMO systems. The performance of single and multiuser SW MIMO systems is analyzed using the developed channel model. Specifically, beamforming performance is evaluated under various receiver architectures, highlighting the impact of distorted steering vectors in beamforming due to high MC. Our studies show that strong MC inherently reduces the effective spatial correlations in SW MIMO arrays, assisting faster channel hardening and enhancing favorable propagation. We also investigate uplink multi-user systems through both orthogonal scheduling and linear combining techniques for these SW MIMO systems.