Performance of generalized Rake receiver with imperfect channel and interference estimates

The Rake and the generalized Rake (G-Rake) receivers are the most commonly used receiver structures in cellular DS-CDMA systems. In this paper we analyze how imperfect channel and noise correlation estimates affect the G-Rake and Rake receiver performances in terms of SIR degradation compared to SIR achieved assuming ideal channel and noise correlation information. The expressions derived in the paper gives a possibility to do model validation. For instance, for the G-Rake case, one can get an indication about the optimal number of probing fingers to be used to maximize the SIR into the detector as function of the number of symbols used for channel and noise covariance estimation. Some performace examples are given in the paper within the framework of WCDMA.