Low-complexity multiuser detector for coherent and incoherent CDMA mobile radio communications

This paper deals with a multiuser detector based on a decorrelating approach for asynchronous up-link DS/CDMA communications in which QPSK modulation schemes are used in transmission and coherent and incoherent receivers in reception. It is shown here that the receivers proposed are near-far resistant and exhibits lower complexity than the optimum detector. The incoherent realization allows a lighter complexity overhead for the synchronization circuitry. The receivers performance is expressed in terms of the bit error rate (BER) which has been derived by simulations under the assumption of a slowly frequency-selective Rayleigh fading channel.