Bilinear Precoder Based Efficient Rate Splitting Method in FDD Systems
Sadaf Syed, Donia Ben Amor, Michael Joham, Wolfgang Utschick · 2025
In this work, we propose a low-cost rate splitting (RS) technique in a multi-user multiple-input singleoutput (MISO) system operating in frequency division duplex (FDD) mode. The proposed iterative optimisation algorithm only depends on the second-order statistical channel knowledge and the pilot training matrix. Moreover, it offers a closed-form solution in each update step. This reduces the design complexity of the system as we only need to optimise the precoding filters in every coherence interval of the covariance matrices, but not in the channel coherence interval. Moreover, since the algorithm provides a closed-form solution, we do not need any interior point solvers like CVX, as needed in most state-of-the-art techniques.