Provided are a device and a method which are capable of performing crosstalk-removed high-quality data reproduction from a high-density recording type optical disc. The device includes a photo detector that outputs a readout signal from a reproduction track of an information recording disc, an adjacent track reproduction binary signal supply unit that outputs a binary signal (binary data) which is a reproduction signal of an adjacent track of the reproduction track, a multi-input adaptive equalizer that includes an equalizer unit that receives the readout signal from the reproduction track and an adjacent track reproduction binary signal and outputs an equalization signal by an adaptive equalization process based on an input signal, and a binarization processing unit that executes a binarization process based on the equalization signal and generates a reproduction signal of the reproduction track.

An apparatus may include a circuit including a filter configured to update one or more adaptive coefficients of the filter based on an error signal. Further, the circuit may update a constrained coefficient of the filter based on the one or more adaptive coefficients, the constrained coefficient and a desired value. Moreover, the circuit may generate a sample of a sample sequence based on the one or more adaptive coefficients and the updated constrained coefficient, the error signal being based on the sample sequence.

A storage device includes read circuitry having a read head having a detector that outputs signals representing data from a first track and an adjacent track. The read head is subject to off-track excursions during which the read head detects signals from both the first track and an adjacent track. Data on each track includes a preamble including a repeating pattern. The repeating pattern in any first track is orthogonal to the repeating pattern in any track adjacent to the first track. The read circuitry also includes respective Discrete Fourier Transform circuits to identify components in the signals corresponding to respective frequencies characteristic of the repeating pattern on the first track and the repeating pattern on the second track, and computation circuitry to determine from the components a ratio by which the read head is off-track. Corresponding methods are provided for operating such a storage device and for reading data.

An optical medium reproduction apparatus for optically reproducing an optical medium, including: a detection unit for splitting a cross section of a beam returned from the optical medium into a plurality of regions and for forming respective detection signals; a multiple input adaptive equalizer having a plurality of adaptive equalizer units, wherein the respective detection signals are inputted into the adaptive equalizer units, and the outputs of the adaptive equalizer units are computed to form equalization signals; a binarization unit for binarizing the equalization signals to provide binary data; and an equalization error computing unit for determining an equalization error from equalization target signals provided based on the binary data from the binarization unit and the equalization signals, and providing the adaptive equalizer units with the equalization error as control signals for adaptive equalization.

There is provided a recording adjustment device, a recording adjustment method, and a program of which enables recording compensation for an optical disc for a high-linear density to be realized. The recording adjustment device according to an embodiment of the present technique executes filter processing on the basis of a regenerative signal obtained by reproducing data recorded in a recording medium, and a recording pattern of marks and spaces of the data, identifies an impulse response of a system, calculates a difference in amplitude between an output from the filter processing after the identification of the impulse response and the regenerative signal every edge type, and detects a slope of a step response in the vicinity of an edge position.

A cross section of a luminous flux of returning light from a disc is split into a plurality of regions, and an operation is performed so that a weighting of a light amount of a region which has favorable symmetry in a radial direction and is formed on a circumference of an ellipse among the split regions is increased. Further, a lens shift detection signal is formed, and a lens shift detection signal is canceled from a push-pull signal.

A computer program product, according to one embodiment, includes a computer readable storage medium having program instructions embodied therewith, wherein the computer readable storage medium is not a transitory signal per se, the program instructions executable by a processing circuit to cause the processing circuit to perform a method that includes reading data from a magnetic data storage medium. The processing circuit uses a tracking threshold module to detect and track positive peak amplitudes and negative peak amplitudes of a readback waveform during the data reading. Asymmetry compensation is performed on the data based on input from the tracking threshold module. The asymmetry compensation does not rely on an input except from the tracking threshold module in order to perform the asymmetry compensation.

In an apparatus configured to perform signal processing on audio data of a first sampling rate, methods disclosed herein comprise receiving audio data of a second sampling rate, the second sampling rate being higher than the first sampling rate. The methods comprise applying filtering to the audio data of the second sampling rate to thereby produce first filtered audio data and second filtered audio data, the first filtered audio data comprising mainly component frequencies which are audible to the human ear, the second filtered audio data comprising mainly components frequencies which are substantially inaudible to the human ear. The methods further comprise applying first signal processing to the first filtered audio data; and applying second signal processing to the second filtered audio data, the second signal processing having a lower computational complexity than the first signal processing. Corresponding apparatus and computer readable media are also disclosed herein.

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.