Patent ID: 7047472

Claim:
An apparatus comprising: first, second, and third memories for storing, respectively, a received signal comprising a sequence of symbols generated from a noise-free signal by a channel that introduces noise, information specifying the probability that a symbol having a value I was converted to a symbol having a value J by said channel, and information specifying a signal degradation function that measures signal degradation resulting from a symbol having the value I being replaced by symbol having a value J; a controller that generates a processed signal from said received signal by replacing symbols in said received signal, wherein said controller replaces each symbol having a value I in a context of that symbol in said received signal with a symbol having a value J if said replacement is estimated to reduce the overall signal degradation in said processed signal relative to said noise-free signal as measured by said signal degradation function, said context comprising a sequence of symbols having fixed values and in a predetermined location with respect to said symbol being replaced.