Decentralized Feedforward-Feedback Interference Cancellation-Based Detector for M-MIMO Systems

Decentralized baseband processing (DBP) has been considered a promising solution to tackle the excessive computational complexity and substantial interconnection costs challenges faced by centralized implementations in massive multiple-input multiple-output (M-MIMO) systems. However, most existing decentralized detectors experience considerable performance degradation resulting from limited information sharing among antenna clusters. In this letter, we propose a decentralized feedforward-feedback interference cancellation (FFIC) detection paradigm for DBP architectures, which is well-suited for message-passing-based nonlinear detectors. The expectation propagation (EP) algorithm is employed as an illustrative example. Simulation results demonstrate that the proposed FFIC-EP detector yields significant performance improvements compared to conventional methods, providing a flexible trade-off between performance, complexity, and interconnection costs, especially in scenarios with low BS-antenna-to-user ratios.