Low complexity multiuser detection based on reliable samples

A sub-optimum multiuser detector which compares the received samples to reliability thresholds, in order to classify them as reliable or non-reliable, is proposed for CDMA systems. Each one of these classified samples receives a different management in the detection process. This technique presents a good trade-off between performance and complexity in relation to the optimum multiuser detector. In fact, for some values of the reliability thresholds, the proposed detector reaches the optimum multiuser detector performance with a much smaller complexity. Theoretical equations and results of simulation for the complexity and bit error rate are presented. The proposed theoretical expressions are very tight when compared to the respective simulation results.