Selectively removing sequences from an enumerative modulation code
AssigneeCirrus Logic, Inc.
InventorsStephen Alan Turk, Christopher Paul Zook
Life of this patent
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Abstract
An encoder/decoder (ENDEC) avoids undesired sequences in encoded data blocks, such as quasi-catastrophic sequences, by essentially skipping over inputs that create the undesired sequences. Upon recognizing that a particular incoming data block has a value corresponding to an undesired sequence, the ENDEC does not use the problematic value for the incoming data block, but rather adds an offset to the value for the incoming data block, and uses the offset value for producing an encoded output sequence for the data block.
Claims43
An encoder which receives an incoming data block and which generates an output data sequence therefrom, and which avoids generating an undesirable output data sequence by adding an offset value to the incoming data block if the incoming data block is not less than a problematic input value, the problematic input value being a value which would encode to an undesirable output sequence.
A decoder comprising:
- a decoder main stage which receives an encoded data sequence and generates an at least partially decoded sequence therefrom;
- a remove offset unit which forms a decoded codeword by removing an offset value from the at least partially decoded sequence, the offset value having been included to avoid encoding an undesirable data sequence.
A method of encoding an incoming data block comprising:
- adding an offset value to the incoming data block to obtain an offset input value if the incoming data block is not less than a problematic input value, the problematic input value being a value which would encode to an undesirable output sequence;
- encoding the offset input value to obtain an output data sequence.
A method of decoding comprising:
- receiving an encoded data sequence and generating therefrom an at least partially decoded sequence;
- forming a decoded codeword by removing an offset value from the at least partially decoded sequence, the offset value having been included to avoid encoding an undesirable data sequence.
Dependencies are inferred from the claim text.