We design a diversity structure of CDMA multiuser detector for frequency selective Rayleigh fading channels. The multiuser detection algorithms for Gaussian channel can be effectively employed in the Rayleigh fading channel through the structure. Simulation results show that the diversity combining of multiuser detection will significantly improve the probability of error in the fading channel
and its capability for dealing with the multi-access interference will not be affected by multiuser detection algorithms. Furthermore
the comparison is made between different combiners and different detection algorithms.