Performance comparisons of iterative multiuser detection techniques in synchronous coded CDMA systems

In this paper, existing iterative multiuser detection techniques, including the iterative (turbo) soft interference cancellation, the iterative improved parallel interference cancellation, the gradient descent algorithm and the slowest-descent search algorithm, are studied. Two new iterative multiuser detection methods, namely, the simplified iterative soft interference cancellation, and the iterative slowest-ascent search algorithm, are developed and are compared with the above techniques. It is seen that the simplified iterative multiuser detection method significantly outperforms the other methods in coded CDMA systems except the turbo receiver, in additive white Gaussian channels, and also it has low complexity.