A low-complexity multiuser detector for asynchronous CDMA QPSK systems

This paper deals with a multiuser detector based on a new decorrelating approach for asynchronous up-link DS/CDMA communications in which the QPSK modulation scheme is used in transmission. It is shown that the receiver proposed is near-far resistant and exhibits a low complexity which allows real-time operation. The performance is expressed in terms of the bit error rate (BER) which has been derived by simulations under the assumption of a slow frequency-selective Rayleigh fading channel.