Optimum transmitters and receivers for CDMA systems

To maximize the CDMA system capacity, we propose to minimize the total transmitted power of the system via designing optimum transmitter sequences and utilizing linear optimum receivers (MMSE receiver) subject to users´ signal-to-interference ratio (SIR) requirements. In our work on joint transmitter-receiver design for multiple antenna CDMA systems with multipath channels, we concentrate on the downlink. Here, we develop optimization algorithms and prove their convergence. We empirically observed that under the optimization algorithm with no constraint on the system, the optimum receiver structure matches the received transmitter sequences. An experiment is performed to see how the different practical system constraints penalize the system with respect to the optimum scheme with no constraint on the system.