A new projection receiver for coded synchronous multi-user CDMA systems

Research into multiuser receivers for code-division multiple-access (CDMA) networks has become increasingly more popular. Multiuser detectors treat the interference from other users in the same frequency band as an information bearing part of the signal, rather than as noise. It is known that optimal near-far resistance and significant performance improvements can be achieved by an optimal multi-user detector. We study a very promising detector structure for coded CDMA, termed the projection receiver (PR), whose structure is built on the decorrelating detector. In the PR the effect of the interfering users is accounted for by metric adjustments, upon which the forward error control decoder operates. The actual interference resolution has a complexity which is proportional to the number of users, and all that is required are single user error control decoders.