  In this paper, the uplink direct sequence code division multiple access
(DS-CDMA) multiuser detection problem (MuD) is studied into heuristic
perspective, named particle swarm optimization (PSO). Regarding different
system improvements for future technologies, such as high-order modulation and
diversity exploitation, a complete parameter optimization procedure for the PSO
applied to MuD problem is provided, which represents the major contribution of
this paper. Furthermore, the performance of the PSO-MuD is briefly analyzed via
Monte-Carlo simulations. Simulation results show that, after convergence, the
performance reached by the PSO-MuD is much better than the conventional
detector, and somewhat close to the single user bound (SuB). Rayleigh flat
channel is initially considered, but the results are further extend to
diversity (time and spatial) channels.
