US 11,145,331 B1 · Systems and methods for adaptation of a two-dimensional magnetic recording channel

Abstract

Systems and methods for adaptation of a two-dimensional magnetic recording (TDMR) channel are provided. Read-back signals from respective read sensors of a TDMR channel are received at an equalizer, the read-back signals corresponding to a digital signal value. A log-likelihood ratio (LLR) signal is generated based at least in part on the read-back signals. A cross-entropy value is generated indicative of a mismatch between a probability of detected bit and a probability of the true recorded bit. The equalizer is adapted by setting an equalizer parameter to a value that corresponds to a minimum cross-entropy value from among the computed cross-entropy value and one or more previously computed cross-entropy values, to decrease a read-back bit error rate for the TDMR channel.

Claims36

Dependent claims

A method for adaptation of a two-dimensional magnetic recording (TDMR) channel, comprising:

receiving, at an equalizer, read-back signals from respective read sensors of a TDMR channel, the read-back signals corresponding to a digital signal value;
generating a log-likelihood ratio (LLR) signal based at least in part on the read-back signals;
computing a cross-entropy value indicative of a mismatch between a probability of detected bit and a probability of the true recorded bit;
and
adapting the equalizer by setting an equalizer parameter to a value that corresponds to a minimum cross-entropy value from among the computed cross-entropy value and one or more previously computed cross-entropy values, to decrease a read-back bit error rate for the TDMR channel.

2 more elements

A two-dimensional magnetic recording (TDMR) read-back channel, comprising:

equalizer circuitry configured to execute an equalization algorithm upon read-back signals received from respective read sensors, the read-back signals corresponding to a digital signal value;
soft sequence detector for an inter-symbol interference (ISI) channel circuitry configured to generate a log-likelihood ratio (LLR) signal based at least in part on the equalized read-back signals;
and
cost function circuitry configured to:
compute a cross-entropy value indicative of a mismatch between a probability of detected bit and a probability of the true recorded bit, and
adapt the equalization algorithm by setting an equalizer parameter to a value that corresponds to a minimum cross-entropy value from among the computed cross-entropy value and one or more previously computed cross-entropy values, to decrease a read-back bit error rate for the TDMR channel.

3 more elements

Dependencies are inferred from the claim text.

Systems and methods for adaptation of a two-dimensional magnetic recording channel

Life of this patent

Systems and methods for adaptation of a two-dimensional magnetic recording channel

Life of this patent

Abstract

Claims36