Patent ID: 6313963
Filing Date: 2001-11-06
Classification: G11B

Abstract:
A method for compensating for partial erasure in a read channel read back of signals from a recording medium, comprising:receiving a signal at a first state of a state machine, said first state having a branch extending to each of a plurality of possible next states of said state machine, wherein each branch corresponds to a target value, wherein said state machine has a total number of states and target values corresponding to the transfer function of the read channel independent of the compensation for partial erasure;determining a partial erasure compensation for each of said target values corresponding to a branch between the first state and each of the possible next states based upon said first state and each of said possible next states, said partial erasure compensation is a function of an amplitude reduced by partial erasure; andmodifying said target value with said determined partial erasure compensation,wherein the steps of determining and modifying are performed within branch metric computations of sequence detection in said read channel.