WLC06-5: A Novel Nonlinear Joint Transmitter-Receiver Processing Algorithm for the Downlink of Multi-User MIMO Systems

A novel nonlinear joint transmitter-receiver processing algorithm is proposed for the downlink of multi-user MIMO systems with multiple-antenna mobiles. In this algorithm, linear receiver processing is applied at each mobile, while nonlinear pre-processing is applied at the base station. Using the zero-forcing (ZF) criterion, the transmitter and receiver processing matrices are designed jointly to optimize the performance of each mobile. When used on the downlink of multi-user MIMO systems with multiple-antenna mobiles, this algorithm achieves significantly better performance than the ZF criterion based pre-processing and joint transmitter-receiver processing algorithms known in the literature, because it successfully constrains the transmitted power increase and effectively utilizes the processing capabilities of the mobiles. For the proposed algorithm, it is found that better system performance can be achieved by suitably ordering the channel matrices of different mobiles, and a combined optimal diversity "best-first" (CODBF) ordering method is proposed to perform the ordering.