Patent ID: 7089483

Claim:
A maximum likelihood detector for use within a partial response channel having a channel transfer function and passing user information sequences encoded into code words in accordance with a channel code, the maximum likelihood detector comprising: a channel sampler for generating raw samples from the code words; a channel equalizer for generating equalized samples from the raw samples using the channel transfer function; a first-stage detector for generating unchecked code words from the equalized samples, wherein the first-stage detector is matched to the channel transfer function and the first-stage detector is not matched to the channel code; and a second-stage post-processor for generating corrected code words from the raw samples and the unchecked code words, wherein the second-stage post-processor is matched to the channel code and includes: a parity checker for generating parity error signals from parity errors in the unchecked code words, wherein the parity errors are due to error-events in the unchecked code words; an error metrics generator for generating decision metrics from the raw samples and the unchecked code words using the channel transfer function; a decision metrics filter for generating most likely error-events by comparing the error-events with predetermined error-events using the channel code; and a code word corrector that generates the corrected code words by removing the most likely error-events from the unchecked code words using the parity error signals and the decision metrics, wherein the most likely error-events include one error-event contained within a single unchecked code word, one error-event straddling two adjacent unchecked code words, multiple error-events contained within a single unchecked code word, and multiple error-events at least one of which straddles two adjacent unchecked code words.