Rate Splitting in FDD Massive MIMO Systems Based on the Second Order Statistics of Transmission Channels

In this work, we present new results for the application of rate splitting multiple access (RSMA) to downlink (DL) a massive multiple-input-multiple-output system (MIMO) operating in frequency-division-duplex (FDD) mode. We propose statistical precoding design relying on channels’ second-order information when one-layer RS is implemented. The advantage lies simplifying precoder by basing optimization objective slowly-varying channel covariance matrices instead fast-changing instantaneous estimates. To end, use so- called bilinear precoder, which was shown Neumann et al. (2018) and Ben Amor (2020) have limited performance high SNR regime due imperfect state (CSI) available at base station (BS). formulate DL throughput maximization problem based widely used lower bound achievable sum an iterative approach solve underlying problem. Numerical demonstrate benefit implementing RS. Furthermore, proposed achieves excellent terms spectral efficiency compared state-of-the-art techniques.