Multiuser Detection in CDMA MIMO Systems with Timing Mismatch
Robert Chao, Yung Lu · 2004
Today, in this information-hungry society, Internet traffic such as multimedia streaming applications is driving the demand for high speed data packet wireless services. The use of multiple transmit and receive antennas has been proposed for the fourth generation code-division multiple access (CDMA) wireless cellular networks in order to meet these demands. Multiuser CDMA multiple-input multiple-output (MIMO) systems have just recently been studied. Receivers proposed for such systems thus far have been based on the assumption that perfect knowledge of the channel state information is available. Although the effects of channel correlation and imperfect estimation on the MIMO system have been rigorously studied, little or no attention has been paid to time-delay mismatch. More importantly, it is well known that timing estimation errors in a CDMA system can result in significant performance degradation, where the near-far resistant property of multiuser detectors is compromised. In this thesis, we investigate the impact of mismatch in time-delay estimations