Cycle-slip resilient iterative data storage read channel architecture

摘要

According to one embodiment, a magnetic medium's readback signal samples are processed iteratively to provide a slip-resistant read channel by feeding the decoder output decisions back to the read channel front end where they are used to drive the decision-aided digital signal processing functions and control loops. Since data decisions provided by the decoder are typically more reliable than those provided by the detector, a significant performance improvement is obtained. A more reliable operation of the digital front-end signal processing functions in turn allows improvements to the reliability of the decoded data. Usage of Error Correcting Code (ECC) schemes that are soft decodable makes the read channel technique, described according to various embodiments herein, particularly efficient.

主权项

1. A system for cycle-slip resilient iterative read channel operation, the system comprising a processor and logic integrated with and/or executable by the processor, the logic being adapted to:
execute cycle-slip detection on a block of signal samples to detect one or more cycle-slip events employing a set of decisions provided by a detector executing a detection algorithm to produce one or more cycle-slip pointers indicating a cycle-slip event; execute one or more additional digital front-end (DFE) functions on the block of signal samples employing the set of decisions provided by the detector executing the detection algorithm; execute a decoding algorithm of an error correcting code (ECC) on the signal samples using a decoder employing the set of decisions provided by the detector to generate a set of decisions provided by the decoder; store the signal samples, the set of decisions provided by the detector, and the set of decisions provided by the decoder; and in an iterative process until a maximum number of iterations has been reached or a valid codeword is produced:
execute cycle-slip detection on the signal samples to detect one or more cycle-slip events employing the set of decisions provided by the decoder;alter a timing estimate used in a phase-locked loop (PLL) of the detector, in one or more subsequent passes, during any time interval determined to experience a cycle slip in the first pass, as indicated by the one or more cycle-slip pointers;execute the one or more DFE functions on the signal samples employing the set of decisions provided by the decoder;execute the detection algorithm on the signal samples using the detector employing the set of decisions provided by the decoder to regenerate the set of decisions provided by the detector;execute the decoding algorithm of the ECC using the set of decisions provided by the detector to regenerate the set of decisions provided by the decoder;output decoding information relating to the signal samples when the decoding algorithm produces a valid codeword; andstore the signal samples, the set of decisions provided by the detector, and the set of decisions provided by the decoder when the decoding algorithm does not produce a valid codeword.