Bit Error Probability of a Rapidly-Adapting Rake Receiver as a Function of Dwell Time

Implementable rake receivers have less correlators than there are propagation paths in the channel. In the case of slowly time-variant channels the rake receiver is able to adapt to the channel by selecting the paths with the maximum momentary power [Gue92a, Gue92b]. In practice, it is not possible to select the best paths for every modulation interval. The bit error probability of rake receivers is calculated for the situation that the path selection is maintained over xed time periods, the dwell time. The results show that the degradation to an instantanous adaption is insigni cant as long as the dwell time is less than ve per cent of the inverse of the fading bandwidth.