Techniques for reducing error propagation using modulation codes having a variable span
AssigneeHitachi Global Storage Technologies Netherlands B.V.
InventorsMario Blaum, Ksenija Lakovic
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Abstract
Techniques are provided for reducing error propagation in encoded data using Fibonacci modulation codes. The Fibonacci modulation codes have a Fibonacci base with a variable span that limits error propagation. Some of the elements in the Fibonacci base have a larger span than limited span elements in the base. Errors occurring in bit positions of an encoded sequence that correspond to the limited span elements do not propagate to adjacent bytes in the decoded sequence. The Fibonacci modulation codes can also have a relatively high code rate.
Claims20
A system for imposing modulation constraints on input sequences to remove a subset of the input sequences, the system comprising:
- a modulation encoder that encodes input sequences to generate encoded sequences using a Fibonacci base having a variable span;
- and
- a modulation decoder that decodes the encoded sequences using the Fibonacci base to generate decoded sequences.
A method for imposing modulation constraints on input sequences to remove a set of forbidden input sequences, the method comprising:
- encoding the input sequences with a modulation encoder to generate encoded sequences using a Fibonacci base with a variable span;
- and
- decoding the encoded sequences with a modulation decoder to generate decoded sequences using the Fibonacci base, wherein a subset of elements in the base have a limited span that prevents errors occurring in a corresponding subset of bit positions in the encoded sequences from propagating to adjacent bytes in the decoded sequences.
A controller for imposing modulation constraints on input sequences, the controller comprising:
- a modulation encoder that encodes input sequences to generate encoded sequences using a Fibonacci base having a variable span;
- and
- a modulation decoder that decodes the encoded sequences using the Fibonacci base to generate decoded sequences, wherein a subset of elements in the Fibonacci base have a limited span that prevents errors occurring in bit positions of the encoded sequences that correspond to the subset of elements from propagating to adjacent bytes in the decoded sequences.
Dependencies are inferred from the claim text.