Patent ID: 8085883

Claim:
A method comprising: obtaining, from an analog to digital converter, a plurality of data samples at a plurality of time indices; calculating, by a branch error metric (BEM) block of a circuit, branch error metrics for the plurality of time indices in response to the plurality of data samples; calculating, by at least one candidate path identification (CPI) block of the circuit, path metrics in a time-reverse order using the branch error metrics, wherein calculating path metrics in a time-reverse order comprises: calculating a plurality of end portions of the path metrics, wherein each of the end portions of the path metrics are based on branch error metrics having latest time indices of the plurality of time indices, and wherein each one of the end portions is associated with a respective plurality of symbol sequences; comparing the plurality of end portions of path metrics to eliminate paths corresponding to the end portions having a large path metric; and calculating a plurality of earlier portions of the path metrics, wherein each of the earlier portions of the path metrics are based on the end portions of path metrics and on branch error metrics having earlier time indices, and wherein each one of the earlier portions is associated with a respective plurality of symbol sequences; identifying, by the at least one CPI block of the circuit, a minimum path metric; and, identifying, by the at least one CPI block of the circuit, a data symbol sequence corresponding to the minimum path metric.