A flexible sliding correlator for use in a spread spectrum receiver divides baseband signal samples into different groups, associates each group with a different section of a spreading code, and combines ones of the signal samples with corresponding values in the spreading code section. The groupings and spreading code sections can be changed during operation of the receiver to maximize performance of the receiver under different or changing conditions. In addition, the sample and spreading code value combinations can be further combined in different ways, and the further combinations can be changed during operation of the receiver. According to another aspect of the invention, the baseband signal can be sampled either uniformly or non-uniformly. The phase and frequency of the baseband sampling can be adjusted during operation of the receiver so that samples are taken very close to the optimum sampling position, at the peak of a chip waveform in the baseband signal.