Iterative PIC detection and channel estimation for DS-CDMA 3G communications

This paper presents a turbo multiuser detector for turbo-coded DS-CDMA systems, based on the utilization of a PIC and a bank of turbo decoders in which the PIC performs interference cancellation after each constituent decoder of the turbo decoding scheme. Moreover, the soft output of the turbo decoders are used iteratively to improve the updating step of the channel parameter estimation which is formally equivalent to one step of the expectation-maximization algorithm. By means of computer simulations, we have shown that the proposed receiver achieves performance comparable with systems which suppose perfect channel parameters knowledge for medium to high system loads in AWGN channel. The proposed receiver is also tested in a satellite channel.