Reduced complexity MAP-based iterative multiuser detection for coded multi-carrier CDMA systems

In previous years, combining multiuser detection (MUD) and channel decoding has received considerable attention. The maximum a posteriori (MAP) criterion based iterative multiuser detector greatly improves the system performance and can approach the performance of single user coded systems even for moderate signal-to-noise ratios. However, its complexity increases exponentially with the number of users, and can become prohibitive for systems with medium to large number of users. A reduced complexity MAP-based iterative MUD based on the use of a soft sensitive bits algorithm is proposed for multi-carrier CDMA systems. It is shown that it can greatly reduce the computational complexity with a minimal penalty in performance compared to the conventional optimal scheme.