Efficient Precoding for Massive MIMO Downlink Under PA Nonlinearities

Abstract : This letter investigates the compensation of the power amplifier (PA) nonlinear distortion (NLD) in large-scale multi-user (MU) multiple-input multiple-output (MIMO) downlink systems. We introduce a PA-aware precoding approach that exploits the high-dimensional degrees of freedom (DoFs), allowed by equipping the base station (BS) by a high number of antennas, and performs the precoded signals that when amplified and passed through the channel, guarantee excellent transmission quality. Specifically, we formulate the proposed PA-aware precoding approach as a simple convex optimization problem which enables efficient, low-complexity, and reliable algorithm implementations. The simulation results demonstrate the strong potential of the proposed approach in terms of improving the link quality and reducing the required computational complexity.