Two-stage nonlinear detector in DS/SSMA communications with impulse noise

A new two-stage nonlinear detector for synchronous DS/SSMA communications in impulsive channels is presented and analysed. In the detector, an interference cancellation scheme is used such that the effect of the multiple-access interference on the system performance can be alleviated. For a multiuser system with long spreading sequences an approximate error probability is derived and shows that the new detector is insensitive to the ‘near–far’ effect and gives a near-single-user performance. For cases with short spreading sequences Monte-Carlo simulation is carried out to estimate the error probability and the results show that the detector performs robustly in various mixtures of noise.