An improved decorrelator-based multiuser receiver

In this paper an algorithm based on the decorrelator multiuser detector is proposed. The main achievement is the introduction of an architecture, which is moderately more complex than, but offers a superior performance to, the decorrelator receiver. The conventional receiver is optimized to combat the Additive white Gaussian noise (AWGN), while the purpose of the decorrelator receiver is the complete elimination of the multiple access interference (MAI). The proposed algorithm uses the conventional detector output in conjunction with the decorrelator output in arriving at its decisions, therefore a substantial improvement could be expected. For a synchronous CDMA system, our simulation results show a significant improvement over the decorrelator receiver. Using our scheme, the degradation factor of a synchronous CDMA system is reduced by more than 6 dB compared to the decorrelator receiver. The proposed algorithm is only slightly more complex than the decorrelator receiver.