Loading patent…
AssigneeCirrus Logic, Inc.
InventorMarvin L. Vis
Estimating the term…
A sampled amplitude read channel is disclosed for magnetic disk storage systems comprising an adaptive non-linear correction circuit for correcting non-linear distortions in the read signal, such as asymmetry caused by the non-linear response of a magneto-resistive (MR) read head. The analog read signal is sampled and the discrete time sample values equalized into a desired partial response prior to sequence detection. The non-linear correction circuit is inserted into the read path prior to the sequence detector and adaptively tuned by a least-mean-square (LMS) adaptation circuit. In one embodiment, the non-linear correction circuit is a discrete-time Volterra filter comprising a linear response for implementing an equalizing filter, and a non-linear response for attenuating non-linear distortions in the read signal. The filter coefficients of both the linear and non-linear sections of the Volterra filter are adaptively adjusted by the LMS adaptation circuit. In an alternative embodiment, the non-linear correction circuit operates in the analog domain, prior to the sampling device, where the cost and complexity can be minimized. The analog correction circuit implements an inverse response to that of the non-linearity in the read signal, and the response is adaptively tuned using an LMS update value computed in discrete-time for a Volterra filter, without actually implementing a Volterra filter. Further, the LMS update value for the analog correction circuit can be implemented using a simple squaring circuit.
A sampled amplitude read channel for reading data recorded on a magnetic disk storage medium by detecting an estimated binary sequence from a sequence of discrete-time sample values generated by sampling an analog read signal emanating from a magneto-resistive (MR) read head positioned over the magnetic disk storage medium, the sampled amplitude read channel comprising:
A sampled amplitude read channel for reading data recorded on a magnetic disk storage medium by detecting an estimated binary sequence from a sequence of discrete-time sample values generated by sampling an analog read signal emanating from a read head positioned over the magnetic disk storage medium, the sampled amplitude read channel comprising:
A sampled amplitude read channel for reading data recorded on a magnetic disk storage medium by detecting an estimated binary sequence from a sequence of discrete-time sample values generated by sampling an analog read signal emanating from a magneto-resistive (MR) read head positioned over the magnetic disk storage medium, the sampled amplitude read channel comprising:
A sampled amplitude read channel for reading data recorded on a magnetic disk storage medium by detecting an estimated binary sequence from a sequence of discrete-time sample values generated by sampling an analog read signal emanating from a read head positioned over the magnetic disk storage medium, the sampled amplitude read channel comprising:
Dependencies are inferred from the claim text.