The effect of channel estimation errors on RAKE receiver performance in WCDMA systems

The performance of a RAKE receiver in a mobile terminal is analysed for a WCDMA downlink. Bit error rates as a function of signal-to-noise ratio are computed for the case when channel estimates are in error as a result of self-interference due to multipath propagation and thermal noise. Channel estimation errors are described using Gaussian approximations for interference and noise, while the effects of self-interference on the data are computed exactly. Results are compared with the case when the receiver has perfect channel knowledge and used to determine a threshold for RAKE finger selection in practical systems.