A decorrelator based successive interference cancellation multiuser multirate receiver

A new decorrelator based successive interference cancellation (DBSIC) multiuser Rake receiver is proposed for asynchronous variable processing gain (VPG) multirate code division multiple access (CDMA) systems over multipath Rayleigh fading channels. By including a decorrelator on top of matched filtering (MF) at each stage of the conventional successive interference cancellation (SIC) receiver to determine the user's signal for the next stage, DBSIC improves the overall system performance at the expense of feasible additional complexity. The simulation results show performance gains for DBSIC over the decorrelating and SIC detectors in the scenario of perfect channel estimation. While it is observed that the system performance degrades under imperfect channel side information, DBSIC consistently outperforms the decorrelating and SIC detectors. It is also shown that while the conventional cancellation/detecting order based on MF outputs outperforms random detecting order for both SIC and DBSIC under perfect or mild imperfect channel estimation, DBSIC performance is less sensitive to the detection ordering method than SIC