Pseudo MIMO (pMIMO): An Energy and Spectral Efficient MIMO-OFDM System

This article introduces an energy and spectral efficient multiple-input multiple-output orthogonal frequency division multiplexing (MIMO-OFDM) transmission scheme designed for the future sixth generation (6G) wireless communication networks. The scheme, termed as “pseudo MIMO,” facilitates the transmission of a greater number of parallel data streams than the number of receiving radio frequency (RF) chains. The approach involves connecting each receiving RF chain with multiple antenna elements and conducting sample-level adjustments for receiving beamforming patterns. The proposed system architecture and the dedicated signal processing methods enable the scheme to achieve a spectral efficiency performance close to that of a fully digital (FD) MIMO system with the same number of antenna elements, each equipped with an RF chain. The article begins with introducing the underlying principles of pseudo MIMO and discussing potential hardware architectures for its implementation. We then highlight several advantages of integrating pseudo MIMO into next-generation wireless networks. Simulation results are presented to demonstrate the superiority of the proposed pseudo MIMO transmission scheme over conventional hybrid and FD MIMO systems in terms of spectral and energy efficiency. Additionally, we validate the feasibility of this new scheme by building the first pseudo MIMO prototype. Furthermore, we present some key challenges and outline potential directions for future research.