Multiuser detectors for MIMO DS/CDMA systems

In this paper, the authors consider a DS-CDMA communication system with K active users. Each user is assigned a unique spreading sequence with finite support. The paper also considers a MIMO channel with N transmitted and M received antennas. The detector has a knowledge of the carrier frequency and phase shift, and cancels out in the receiver front end. The fading is slow such that the channel remains constant during one bit time slot of J chip intervals.