Analytical evaluation of turbo multiuser detection algorithms

Turbo receivers have gained significant importance in recent years, enabling the effect of the interference-limited propagation channel to be overcome through the iterative exchange of information between the front-end receiver and the channel decoder. Such an iterative process is difficult to describe in a closed form, so the performance evaluation is usually done by means of extensive numerical simulations. We propose an analytical method for the performance evaluation of turbo receivers. The proposed approach, based on the so-called EXIT (extrinsic information transfer) analysis, allows for an accurate prediction of the receiver coded BER for each iteration as a function of the channel state. We show the performance analysis of linear turbo receivers applied to multiuser detection in synchronized CDMA.