Robust MIMO-CDMA Decorrelating Detector

The multiuser detection of space coded, multi input multi output (MIMO), code division multiple access (CDMA) signals in the downlink direction with channel estimation error is investigated. The main challenge in the system is dealing with the errors in estimating the channel coefficients at the receiving antennas. The performance of the decorrelating detector (DD) under different channel estimation errors, timing errors, and impulsive noise is investigated. A new robust decorrelating detector (RDD) is proposed which compensates the channel estimation errors by modifying the channel matrix in the system. RDD also deals with the timing errors by the modification of the spreading matrix, and finally, it passes the impulsive components of the additive noise through a robust non-linearity to reduce the impulsive effects. The results show that the performance of the RDD is superior to that of the DD.