Analysis and Mitigation of Phase Noise in a Line-of-Sight MIMO System

We establish a solid foundation for the theory and practice of pilot-based carrier phase synchronization in line-of-sight (LOS) MIMO systems affected by phase noise. LOS MIMO is a multi-antenna technology used in fixed wireless backhaul systems. As part of this, a realistic and simple oscillator phase-locked loop model is employed. To maximize the rate, a novel pilot-based MMSE estimator is formulated to jointly estimate the received symbols and the unknown phase noise at both the transmitter and receiver. Additionally, we demonstrate that effective power allocation, considering phase noise, is crucial for maximizing the rate in phase noise-limited systems.