Combined coding and successive interference cancellation with random interleaving for DS/CDMA communications

The next-generation wireless communication systems are expected to support a broad range of services including communication, information, multimedia and entertainment. In order to meet the increasing demand in capacity and achieve multirate services in the 3G wireless communication systems, wideband code division mltiple access (CDMA) has emerged as the main candidate under consideration. However, because of its inherent multiple access interference, the performance of CDMA can be severely degraded as the number of subscribers increases. Multiuser detection is a scheme which jointly detects all users´ signals and by doing so can offer significant system performance improvement. This paper investigates and analyzes the performance of multiuser successive interference cancellation in a coded wideband DS/CDMA communication system. Specifically, a new multistage interference cancellation method is presented which employs a combined coding, successive interference cancellation and random interleaving. Simulation results demonstrate that the proposed scheme can significantly increase the system capacity and performance