In one embodiment, a system includes one or more processors and logic integrated with and/or executable by the one or more processors. The logic is configured to cause at least one of the processors to detect positive peak amplitudes and negative peak amplitudes of an unequalized readback signal that exhibits imperfect or bi-modal waveform peaks using a peak tracking threshold module positioned at an input to an equalizer. Also, the logic is configured to cause the at least one of the processors to track the positive peak amplitudes and the negative peak amplitudes of the unequalized readback signal in a record. Moreover, the logic is configured to cause the at least one of the processors to provide, as an input to an asymmetry compensator, the record of the peak amplitudes and the negative peak amplitudes determined from the unequalized readback signal.

Systems and methods are disclosed for head delay calibration and tracking multi-sensor magnetic recording (MSMR) systems. In certain embodiments, an apparatus may comprise a first reader and a second reader configured to simultaneously read from a single track of a data storage medium, the first reader offset from the second reader such that the first reader and the second reader detect a same signal pattern offset in time. The apparatus may further comprise a circuit configured to determine a relative offset between the first reader and the second reader, including setting a fixed delay for a first signal from the first reader, setting a second delay for a second signal from the second reader, and adjusting the second delay to align the second signal to the first signal using a timing loop, with the first signal used as a reference signal.

A digital polar transmitter arrangement having a digital front end (DFE) and a transmit chain is disclosed. The DFE is configured to resample a baseband signal relative to a carrier frequency at a carrier frequency related sample rate, calculate zero crossing positions of the resampled signal, generate delay to time converter (DTC) commands based on the zero crossing positions, calculate amplitude values for the zero crossing positions and generate dynamic phase alignment (DPA) commands based on the amplitude values. The transmit chain is configured to generate an output signal having amplitude and phase modulation based on the DTC and DPA commands.

Data detection capability is improved by whitening crosstalk noise from an equalization signal and detecting binary data. Each of a plurality of detection signals is input to one of a plurality of adaptive equalizers, and outputs of the plurality of adaptive equalizers are computed to obtain an equalization signal for returning light at the time of shining of light onto bounds including a target track subject to data detection and adjacent tracks of an optical recording medium having a plurality of tracks formed thereon. Crosstalk noise from the adjacent tracks included in the equalization signal obtained by this multi-input adaptive equalization process is whitened first, followed by a binarization process. Also, an equalization error is found, and supplied as a control signal for adaptive equalization. Further, a whitening factor updating process is also performed to adaptively update a filter factor of a whitening filter.

The present disclosure relates to a method and apparatus for processing of multi-dimensional readback signal from magnetic recording or optical, physical data recording so as to reduce/control Inter Symbol Interference (ISI) and noise within acceptable limits. The method is based on Partial Response Maximum Likelihood (PRML) detection and takes care of time varying channel conditions. In an embodiment, the filter coefficients of both the equalizer and the partial response (PR) target are jointly adapted to account for the channel condition for both separable and non-separable targets thus reducing signal detection complexity. In an aspect, the disclosure provides an apparatus that incorporates an adaptation engine along with the equalizer and the PR target that updates filter coefficients of both the equalizer and the PR target following the formulated mathematical equations.

In one embodiment, a system includes one or more processors and logic integrated with and/or executable by the one or more processors. The logic is configured to cause at least one of the processors to detect positive peak amplitudes and negative peak amplitudes of an unequalized readback signal that exhibits imperfect or bi-modal waveform peaks using a peak tracking threshold module positioned at an input to an equalizer. Also, the logic is configured to cause the at least one of the processors to track the positive peak amplitudes and the negative peak amplitudes of the unequalized readback signal in a record. Moreover, the logic is configured to cause the at least one of the processors to provide, as an input to an asymmetry compensator, the record of the peak amplitudes and the negative peak amplitudes determined from the unequalized readback signal.

According to one embodiment, a method for processing data includes directing first data through a first FIR gain module in response to a determination that the first data is being read from a magnetic tape medium in an asynchronous mode to control FIR gain of the first data. The method also includes directing second data through a second FIR gain module in response to a determination that the second data is being read from the magnetic tape medium in a synchronous mode to control FIR gain of the second data. Other systems and methods for processing data using dynamic gain control with adaptive equalizers are presented according to more embodiments.

A method for digital timing recovery from oversampled analog signals includes computing filter coefficients for digitized samples of the oversampled analog signals based on an oversampling factor of the oversampled analog signals, using the filter coefficients in a rotation filter to compensate for the oversampling factor in the digitized samples of the oversampled analog signals, deriving a starting phase and magnitude from the compensated digitized samples of the oversampled analog signals, and using the starting phase and magnitude in a timing recovery loop to recover a clock from the compensated digitized samples of the oversampled analog signals. The rotation filter may include a plurality of taps, and the circuitry may be configured to compute respective sets of coefficients for respective taps. Each set of coefficients may be dependent on another set of coefficients, or the coefficients may be approximate with each set of approximate coefficients being independent.

Systems and method are disclosed relating generally to data processing, and more particularly to systems and methods for utilizing multiple data streams for data recovery from a storage device. One example of the system includes a first equalizer circuit, a second equalizer circuit, a summation circuit, a first multiplication circuit, a second multiplication circuit, and a scalar calculation circuit that is capable of calculating a scalar based upon coefficients that are also provided as inputs to the first equalizer and second equalizer.