Multiuser detection for CDMA systems

Present day direct sequence code division multiple access (DS/CDMA) systems treat each user separately as a signal, with all ofthe other users representing interference or noise. Potentially significant capacity improvements can be achieved if the negative effect that each user has on the others is cancelled. In other words, joint detection (multiuser detection), rather than separate detection, is beneficial. Optimal multiuser detection is, however, too complex. Thus, suboptimal approaches have been investigated. The basic principles of optimal and suboptimal multiuser detection are well understood now and effort is underway on investigating practical and economic feasibility.