Patent ID: 6898379

Claim:
A method of determining a value of a current data bit in an optical data stream by reducing interference caused by one or more (N) prior bits, the method comprising: receiving an electrical signal derived from the optical data stream; creating one or more (X) channels for making tentative decisions as to a value of the current data bit, where X=2 N , each channel being associated with a unique possible value for the N prior bits, each tentative decision made by each channel representing a potential value for the current data bit determined by reducing interference based on the N prior bits corresponding to the unique possible value of the channel; as part of each channel: filtering the electrical signal, utilizing a channel-specific adaptive filter having variable filter coefficients, to generate a filtered output signal; adaptively generating a variable threshold value; comparing the variable threshold value against the filtered output signal to generate a tentative decision for the current data bit; accessing a determined value for the N prior bits from a delayed decision signal; selecting a determined value for the current data bit from among the tentative decisions based on the determined value for the N prior bits; for each particular channel, updating the variable threshold value and the variable filter coefficients of the channel-specific adaptive filter, based upon one or more error signals related to data bits having a determined value corresponding to the particular channel.