Patent ID: 6366418
Filing Date: 2002-04-02
Classification: G11B

Abstract:
A method for reducing data format overhead in a storage device including a sequence detector having a series of states and a path memory of predetermined length, the method including the steps of:writing a predetermined shortened pad pattern at the end of a user data field pattern to a signal-degrading storage medium of the device, generating samples during read back of the user data field pattern and the shortened pattern, and controlling the sequence detector during receipt of samples of the shortened pad pattern to converge to only one or a small number of predetermined states of the sequence detector during a convergence sequence shorter than a sequence needed to traverse the length of the path memory, such that the convergence sequence provides a most likely estimate of a last user data bit of the user data field pattern, and such that the predetermined shortened pad pattern is selected so that paths that diverge from a common state in the sequence detector and reach said small number of predetermined states have a large separation from each other in Euclidean distance thereby enabling accurate selection of a most likely path to a state providing a most likely estimate of a last user data bit of the user data field pattern.