30. A method for performing correlation of a succession of received digital words in a serial bit stream with a reference digital word of bit length L having a reference word period, comprising the following steps: forming a ramp-weighted sum over a plurality of received digital words, said sum comprising the sum of a product of a reference word bit with a product of a corresponding received bit with a ramp weight W(k); forming a uniformly-weighted sum over said plurality of received digital words, said sum comprising the sum of a product of a reference word bit with a corresponding received word bit; and forming a digital correlator output signal, each output signal comprising a triangular-weighted sum of scaled versions of said ramp-weighted sums and said uniformly-weighted sums over said predetermined plurality of received words, whereby degradation of said correlator performance caused by Doppler shift modulation on said received signals is reduced.
30. A method for performing correlation of a succession of received digital words in a serial bit stream with a reference digital word of bit length L having a reference word period, comprising the following steps: forming a ramp-weighted sum over a plurality of received digital words, said sum comprising the sum of a product of a reference word bit with a product of a corresponding received bit with a ramp weight W(k); forming a uniformly-weighted sum over said plurality of received digital words, said sum comprising the sum of a product of a reference word bit with a corresponding received word bit; and forming a digital correlator output signal, each output signal comprising a triangular-weighted sum of scaled versions of said ramp-weighted sums and said uniformly-weighted sums over said predetermined plurality of received words, whereby degradation of said correlator performance caused by Doppler shift modulation on said received signals is reduced. 32. The method of claim 30 further comprising the step of digitally filtering said digital correlator output signals with a digital low-pass filter to attenuate sidebands of uncorrelated signals.