Recursive algorithms for multiuser detection over DS/CDMA channels

We consider the problem of reduced-complexity detection for the synchronous Gaussian direct-sequence code-division multiple access (DS/CDMA) channel. This interest stems from the high computational complexity connected with the implementation of the optimum maximum likelihood (ML) multiuser receiver and from the very poor resistance of the linear receivers to overloaded scenarios, especially in the presence of imperfect power control. We introduce a new family of iterative receivers which yields a very fast convergence with an affordable computational complexity. Moreover the performance assessment conducted via Monte Carlo techniques shows that the novel receivers outperform the linear detectors and achieve a bit error rate close to the optimum even when the number of users approaches the processing gain.