Iterative multiuser detection for space-time coded synchronous CDMA

Multiuser detectors for trellis space-time coded synchronous CDMA, operating in the presence of independent Rayleigh fading are considered. The joint optimal maximum likelihood (ML) multiuser detector, which can be implemented as a Viterbi algorithm, is derived for such space-time coded systems. A suboptimal, low complexity iterative space-time multiuser detector based on interference cancellation and the turbo principle is also derived. Simulations show that this latter method achieves performance competitive with the single user bound for space-time coded systems.