Patent ID: 7277506
Filing Date: 2007-10-02
Classification: H04L

Abstract:
1. A maximum likelihood sequence estimator (MLSE) for estimating a possible sequence of transmitted symbols received over a dispersive communication channel, wherein a trellis of states and trellis paths are associated with the possible sequence of transmitted symbols, said MLSE comprising: a plurality of data sources relating respectively to state transition probabilities and observed values of received data symbols; means for calculating and storing a likelihood metric and a survivor bit for each state of the trellis using values from said plurality of data sources, comprising means for computing branch metrics for the trellis by setting a first portion of the branch metrics equal to a coefficient which models an autocorrelation of an impulse response of a channel and setting a second portion of the branch metrics equal to a sum or difference of a prior value of a branch metric and a coefficient which models an autocorrelation of an impulse response of a channel; means for determination of a final state on a maximum likelihood path in the trellis; and means for calculating a maximum likelihood sequence of transmitted symbols in a backward trace through the trellis using said stored survivor bits.