Patent ID: 6424686
Filing Date: 2002-07-23
Classification: G11B

Abstract:
A method for maximum likelihood detection of digital samples of data recorded as analog signals representing a finite number of maximum likelihood states in accordance with a finite number of maximum likelihood sample-to-sample path cases, said digital samples representing channel output of said recorded analog signals at a predetermined timing with respect thereto, comprising the steps of:applying numerical metric coefficients to each of said digital samples to provide at least one difference metric, each said difference metric derived from the difference between metrics directly associating â€œ0â€  and â€œ1â€  states of said recorded signal for two sequential said digital samples; generating a plurality of alternative metrics related to said digital samples; selecting the one of said respective generated alternative metrics which remains within defined positive and negative bounds by comparing said generated alternative metrics to said difference metric; identifying the one of said finite number of states represented by said selected metric; and responding to said identified one of said finite states, setting a maximum likelihood state detector to a maximum likelihood state dictated by said identified one of said finite states, said set maximum likelihood state detecting said recorded analog signals.