Successive multiuser detection technique in DS-CDMA systems

Abstract

This paper describes a successive multiuser detection technique for Direct Sequence Code Division Multiple Access (DS-CDMA) systems. In conventional CDMA system, single-user detection is employed, so that the interference between users or multiple access interference (MAI) component is considered as noise, which contributes to the statistics of detection variables affecting the quality of detection. In this paper a successive multiuser detection scheeme is proposed to cancell inter user interference. In multiuser detections, the MAI component can be eliminated or cancelled by the use of all user's spreading code in the system. The basic concept of successive multiuser detection technique are described in a simple model and the performance for various number of users is simulated and eavaluated. The performnce of successive multiuser detection is then compared with that of the single-user detection to show a significant improvement.