Abstract:
An optical tape decoding system includes a decoder that may apply a matched pattern signal (72) representing an address index to a track address signal (74)including a multi-cycle wobble block representing the address index such that a signal is output having a peak corresponding to the multi- cycle wobble block. The decoder may also identify the address index based on an amplitude of the peak.
Abstract:
Common sample timing control for sample timing of multiple read channels, wherein the signalclocking of the signals received by the multiple read channels are correlated, for example from parallel tracks of magnetic tape that have been written simultaneously. A common sample timing control comprises multiplephase error inputs (91, 92), each indicating phase error of one of the read channels. Logic responsive to the multiple phaseerror inputs is configured to weight and crosscouple the phase error indication of each phase error input withthe phase error indication of each other phase error input, and to apply gain related to the variance of noise of the phase error indications. Feedback logic (141, 142) is responsive to the crosscoupling and is configured to provide a sample timing phase estimate (111, 112) for each read channel.
Abstract:
An enhanced write splice for optical recording channels is disclosed. Optical control circuitry locks to previously-written data (202) and determines the estimated write splice location. A training sequence (204) is written to the optical medium at a location based on the estimated write splice location. The phase offset (Delta Theta) is then estimated by reading the training sequence (204). A new write splice location may then be calculated compensating for the phase offset estimate (Delta Theta). Finally, the new data to be spliced may be written or overwritten to the channel at the new write splice location.
Abstract:
An apparatus includes a recorder having at least two optical pickup heads for simultaneously recording at least two bit streams on respective layers of recordable media in one of an opposite track path and a parallel track path.
Abstract:
An enhanced write splice for optical recording channels is disclosed. Optical control circuitry locks to previously-written data and determines the estimated write splice location. A training sequence is written to the optical medium at a location based on the estimated write splice location. The phase offset is then estimated by reading the training sequence. A new write splice location may then be calculated compensating for the phase offset estimate. Finally, the new data to be spliced may be written or overwritten to the channel at the new write splice location.
Abstract:
A communication system includes a communication channel (110) for time- synchronous transfer of data symbols a 1 ,..., a N to a receiver (130). A sampling unit (132) is used for time-sequential sampling the channel under control of a sampling clock signal that is synchronous with transmittal of the data symbols. Each sample includes a representation of a data symbol and noise. A data-aided timing error detector (133) receives a representation of the samples. The detector includes a data-dependent noise predictor (310) for generating a predicted noise sequence ñ 1 ,..., ñ N where each predicted noise value n k for the k-th sample of the sequence depends on a cluster of a plurality of sampled data symbols and a noise whitening unit (320) for whitening of noise in the sample sequence by removing the predicted noise value ñ k . The detector is arranged to provide a signal for correcting the sampling clock signal in dependence on the whitened sample sequence.