Dynamic Scheduling for a Turbo CDMA Receiver using EXIT Charts

In this paper we utilize extrinsic information transfer (EXIT) chart analysis in a coded direct-sequence codedivision multiple-access (DS-CDMA) multiuser receiver to dynamically derive the optimal decoding schedule in the unequal user power level case. Conventional receivers generally follow a predetermined decoding schedule. However, decoding delay and complexity can be significantly reduced while maintaining BER performance through optimisation of the decoding schedule. We show dynamic scheduling, that is deriving the optimal schedule on-line after each iteration of the receiver, is a more flexible approach which improves the BER performance in comparison to the static (off-line) optimised schedule for similar complexity savings over the conventional receiver.