Multicarrier CDMA Multiuser Detection Algorithm Based on Belief Propagation

Recently, several published papers have been drawing attention to multicarrier code division multiple access (MC-CDMA) systems, especially their applications in the field of broadband wireless communications. In such applications, existing sub-optimal multiuser detectors (MUDs) usually do not achieve acceptable performance. Unfortunately, it is NP-hard to implement an optimum MUD algorithm. In this paper, to make the optimum MUD feasible, we put together a low-complexity iterative MUD algorithm for MC-CDMA systems based on Pearl´s belief propagation (BP) scheme. The BP-based MUD algorithm can be implemented in a practical time scale. The analytical dynamic bit-error-rate (BER) performance of the BP-based iterative detector can be traced accurately and its BER in the stationary state is shown to achieve the performance obtained by the optimum MUD algorithm