Joint Transmitter-Receiver Design for the Downlink Multiuser Spatial Multiplexing MIMO System

In the multiuser spatial multiplexing Multiple-Input Multiple-Output (MIMO) system, the joint Transmitter-Receiver (Tx-Rx) design is investigated to minimize the weighted sum power under the post-processing Signal-to-Interference-and-Noise Ratio (post-SINR) constraints for all subchannels. Firstly, the authors show that the uplink-downlink duality is equivalent to the Lagrangian duality in the optimization problems. Then, an iterative algorithm for the joint Tx-Rx design is proposed according to the above result. Simulation results show that the algorithm can not only satisfy the post-SINR constraints, but also easily adjust the power distribution among the users by changing the weights accordingly.