Advanced whitener-rake receiver for wcdma terminal

Abstract

A CDMA receiver () includes a receiver input for coupling to signal outputs of Nreceive antennas (A,B), where the signal outputs are sampled at Nsamples per symbol or chip, a matched filter (), such as a RAKE, and a whitening filter () for coupling the receiver input to an input of the matched filter. The whitening filter contains NNparallel whitening filters w(A-D), individual ones of the whitening filters wreceiving during each symbol interval i, NNnew signal samples via a signal connection matrix () such that a first individual whitening filter receives only one of the new samples, a second individual whitening filter receives the same sample as the first individual whitening filter, and one additional sample, and such that an nth individual whitening filter receives the same n−1 samples as the first n−1 individual whitening filters, plus one of the remaining samples. The whitening filter has Noutputs for outputting filtered signal samples such that a filtered signal sample appearing in the Noutputs does not correlate with any other filtered signal sample appearing in Noutputs. The whitening filter also includes a delay line () constructed as a plurality of serially coupled delay line elements each having a delay of one symbol interval. The delay line has an input coupled to an output of said signal connection matrix and provides the NNparallel whitening filters wwith delayed versions of the signal samples.