A Low Complexity Rate-Splitting Bilinear Precoder for Massive MIMO

Abstract:
Realistic massive multiple-input multiple-output (MIMO) systems suffer from incomplete channel state information (CSI) and pilot contamination, due to the dimensionality bottleneck mainly caused by the short channel coherence interval. Recently, rate splitting was proposed as a powerful tool to enhance the system performance in the case of imperfect CSI. In this paper we consider a multi-user massive MIMO broadcast system operating in FDD mode and develop a bilinear precoder combined with rate splitting. To circumvent the high computational complexity introduced by the rate splitting approach, we furthermore develop a low complexity rate splitting algorithm. Finally, we also validate the superiority of the proposed methods over the approach without rate splitting and another recently developed algorithm.