ADAPTIVE DATA-DEPENDENT NOISE PREDICTION (DDNP)

摘要

A data-dependent noise predictive (DDNP) adaptation module operable to support Viterbi branch metric calculations within a hard disk drive (HDD) controller is provided. This DDNP adaptation module includes a DDNP filter tap coefficient adaptation module, a DDNP filter gain scaling module, and a DDNP bias compensation module. The combination of the DDNP filter tap coefficient adaptation module, the DDNP filter gain scaling module, and the DDNP bias compensation module is operable to receive an error signal and a NRZ pattern and produce tap coefficients. A whitened error signal calculation module coupled to the DDNP filter tap coefficient adaptation module, the DDNP filter gain scaling module, and the DDNP bias compensation module, the whitened error signal calculation module operable to calculate a whitened error signal based on the error signal, NRZ pattern, and tap coefficients. This whitened error signal is used to support the Viterbi branch metric calculations.