Receiver and method for processing radio signals using soft pilot symbols

A two-pass generalized Rake (G-Rake) receiver for processing a received radio signal that includes a sequence of transmitted symbols, said receiver comprising:

• means for computing a set of approximate combining weights in a first pass;
• means for identifying a set of soft pilot symbols in the sequence, wherein the soft pilot symbols are modulated with a lower order modulation than the remaining symbols in the sequence;
• means for utilizing the approximate combining weights to coherently combine despread values corresponding to the soft pilot symbols to create symbol estimates;
• means for making hard symbol decisions without decoder involvement on the symbol estimates given the constellation used for transmission;
• means for utilizing the hard symbol decisions as demodulation pilots to nonparametrically estimate an impairment covariance matrix;
• means for computing a set of refined combining weights in a second pass utilizing the estimated impairment covariance matrix;
• and
• means for combining all traffic data utilizing the refined combining weights.