Receiver and transmitter iterative optimization using maximum sum-rate criterion for Multi-User MIMO systems

In this paper we present a new practical method for sum-rate maximization for a Multi-User MIMO system. Through this work, we first establish a general formula for the optimal receiver derived from the sum-rate expression called MSR (Maximum Sum Rate) receiver. The obtained MSR receiver is a linear function of the used linear transmitter. In a second step, we introduce this receiver in an iterative algorithm to derive the corresponding precoder. The proposed iterative algorithm is based on optimizing the MSR receiver for the receiving part and an SJNR (Signal to Jamming plus Interference Ratio) precoder at the transmitter. Simulation results are compared to two multi-user schemes among the existing ones. The first comparison is done with the closed form SJNR algorithm given in and the second one is done with an iterative scheme based on an MMSE receiver and an MMSE precoder given in. These comparisons highlight the gains obtained from both the MSR receiver structure and our iterative procedure.