Patent ID: 8170128

Claim:
A method for estimating symbol values in a communications receiver having a decision feedback equalizer, the decision feedback equalizer including filter and symbol estimation circuitry, the method comprising: in the symbol estimation circuitry coupling at least one coefficient of the filter to the filter and symbol estimation circuitry; calculating a current observation sample using output from the decision feedback equalizer and a coefficient of the filter; calculating a delayed observation sample using the output from the decision feedback equalizer; calculating current trellis transition metrics from a current observation sample and the coefficient of the filter; calculating delayed trellis transition metrics from a delayed observation sample; combining the current trellis transition metrics and the delayed trellis transition metrics with trellis state transition metrics to form trellis branch metrics and trellis branch symbols; and selecting a symbol estimate from said trellis branch symbols and the trellis state metrics from among the trellis branch metrics.