RAKE receiver which, based on channel conditions, adaptively provides the fine timing correction step of adjusting phase of over-sampling

摘要

The invention concerns synchronization in a RAKE receiver. A signal received at a RAKE receiver is sampled and interpolated. Channel conditions such as SNR or/and dispersion are estimated, and based on the estimate a decision is made as to whether to perform a fine timing correction step. The fine timing correction step involves performing a tracking operation on the strongest RAKE finger so as to align the timing of the generation of samples with the timing of the signal and the RAKE finger. Preferably this is achieved through adjusting interpolation filter coefficients to provide an appropriate phase offset correction. The invention thus provides a timing correction mechanism which reduces timing errors without increasing the oversampling factor. Furthermore, the timing correction mechanism is adaptive in the sense that it is used only when required, thereby reducing unnecessary computing power.