Method and apparatus for using dual-viterbi algorithms to estimate data stored in a storage medium

摘要

A system including a storage medium, a demodulator, and a decoder. The demodulator is configured to receive an input signal from the storage medium and demodulate the input signal. The decoder is configured to estimate data stored in the storage medium by decoding the demodulated input signal to provide an output signal. The decoder includes a filter and first and second processors. The filter is configured to generate a first equalized signal based on the output signal. The first processor is configured to, based on the first equalized signal and a first Viterbi algorithm, generate a first estimate of the data and an estimate of noise. The second processor is configured to generate a second estimate of the data based on the first estimate of the data, the estimate of the noise, and a second Viterbi algorithm. The output signal includes the second estimate of the data.