Storage tape wobble decoder and method
AssigneeOracle International Corporation
InventorFaramarz Mahnad
Life of this patent
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Abstract
Amplitude or phase modulated uncompensated wobble patterns representing address patterns for track addresses of optical media are generated or applied to the media. A filter is applied to the un-compensated wobble patterns to detect a threshold value to signal the existence of a synchronization pattern. A pair of filters can be used to detect the threshold and a zero-crossing. This methodology can detect the existence and timing of the wobble pattern. This can eliminate the need for a timing recovery subfield in the wobble pattern of the prior art.
Claims18
A method for decoding a wobble pattern on an optical medium comprising:
- reading a wobble pattern signal on the optical medium, the wobble pattern signal stored in a wobble physical nanostructure track that is smaller than a land and groove structure of the optical medium, the wobble pattern signal representing address patterns for track addresses of the optical medium;
- applying a matched filter to the wobble pattern signal to generate a detection signal when the wobble pattern is detected by the matched filter, wherein applying the matched filter includes applying a sync sine matched filter to the wobble pattern signal;
- and detecting a threshold of the detection signal to indicate a beginning of an address field.
An optical tape data storage system comprising:
- a tape head to read a wobble pattern signal on an optical tape;
- and
- a decoder configured to receive the wobble pattern signal of the optical tape, and filter the wobble pattern signal using:
- a sync sine matched filter to output a first detected signal that crosses a first threshold to identify a timing,
- and a sync cosine filter to output a second detected signal that crosses a second threshold to further identify the timing without a timing recovery signal being present in the wobble pattern signal.
An optical media encoding system, comprising
- an encoder configured to write a wobble pattern signal to an optical tape with a dual pattern wobble signal that is matched to a sync sine matched filter to read a first detected signal that crosses a first threshold to identify a timing and matched to a sync cosine matched filter to read a second detected signal that crosses a second threshold.
Dependencies are inferred from the claim text.