Asymmetry correction in read signal

A system comprising:

• a storage medium;
• a head assembly operable to obtain an analog signal from the storage medium;
• an asymmetry correction circuit configured to receive the analog signal and to compensate for asymmetry in the received analog signal;
• a signal equalizer configured to receive an input signal responsive to an output of the asymmetry correction circuit and to generate an equalized signal;
• a discrete time sequence detector operable to examine the equalized signal;
• and
• a control circuit that provides a coefficient adjustment to the asymmetry correction circuit to affect the asymmetry compensation;
• wherein the coefficient adjustment is based on a correlation between an estimated ideal channel output and an error signal, the estimated ideal channel output being derived from an output of the discrete time sequence detector, and the error signal being derived from the equalized signal and an estimated real equalized channel output with asymmetry taken into account.

A method comprising:

• compensating for asymmetry in an analog signal based on at least one coefficient adjustment;
• equalizing a digital signal obtained by sampling the analog signal;
• detecting a data sequence in the equalized digital signal;
• reconstructing an ideal target channel output from the detected data sequence;
• and
• modifying the at least one coefficient adjustment to affect the asymmetry compensation based on a correlation between the reconstructed ideal target channel output and an error signal derived from the equalized digital signal and the detected data sequence.