8B-16B RLL decoder with hamming distance detection
AssigneesSony Corporation, Sony United Kingdom Limited
InventorJames H. Wilkinson
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Abstract
Apparatus for decoding an input digital signal by replacing successive n-bit groups of the input digital signal with respective ones from an ensemble of m-bit data words, each m-bit data word having an associated n-bit code word, where n is greater than m, comprises: means for determining the Hamming distance between an n-bit group of the input digital signal and each of the n-bit code words associated with the ensemble of m-bit data words; and means for replacing that n-bit group of the input digital signal with an m-bit data word from the ensemble of m-bit data words for which the Hamming distance between the n-bit code word associated with that m-bit data word and that n-bit group is the lowest.
Claims13
Apparatus for decoding an input digital signal comprising successive n-bit groups of data bits by replacing said successive n-bit groups with respective ones from an ensemble of m-bit data words, each said m-bit data word having at least one associated valid n-bit code word, where n is greater than m, said apparatus comprising:
- means for determining a Hamming distance between a current n-bit group of said input digital signal and each of said valid n-bit code words;
- means for detecting whether one or more of said valid n-bit code words each have the lowest Hamming distance from said current n-bit group;
- means, responsive to a detection that only one of said valid n-bit code words has the lowest Hamming distance from said current n-bit group, for replacing said current n-bit group with an m-bit data word from said ensemble of m-bit data words for which said Hamming distance between a valid n-bit code word associated with said m-bit data word and said current n-bit group is the lowest;
- and
- means, responsive to a detection that more than one of said valid n-bit code words have said lowest Hamming distance from said current n-bit group, for replacing said current n-bit group with an m-bit data word associated with one of said more than one valid n-bit code words having said lowest Hamming distance from said current n-bit group when said lowest Hamming distance is equal to one and for replacing said current n-bit group with an m-bit data word for which a bit separation between a valid n-bit code word associated with said m-bit data word and said current group is the lowest when said lowest Hamming distance is not equal to one.
A method of decoding an input digital signal comprising successive n-bit groups of data bits by replacing said successive n-bit groups with respective ones from an ensemble of m-bit data words, each said m-bit data word having at least one associated valid n-bit code word, where n is greater than m, said method comprising the steps of:
- determining a Hamming distance between a current n-bit group of said input digital signal and each of said valid n-bit code words;
- detecting whether one or more of said valid n-bit code words each have the lowest Hamming distance from said current n-bit group;
- replacing said current n-bit group with an m-bit data word from said ensemble of m-bit data words for which said Hamming distance between a valid n-bit code word associated with said m-bit data word and said current n-bit group is the lowest when only one of said valid n-bit code words has the lowest Hamming distance from said current n-bit group;
- and
- replacing, when more than one of said valid n-bit code words have said lowest Hamming distance from said current n-bit group, (i) said current n-bit group with an m-bit data word associated with one of said more than one valid n-bit code words having said lowest Hamming distance from said current n-bit group when said lowest Hamming distance is equal to one and (ii) said current n-bit group with an m-bit data word for which a bit separation between a valid n-bit code word associated with said m-bit data word and said current group is the lowest when said lowest Hamming distance is not equal to one.
Apparatus for decoding an input digital signal comprising successive n-bit groups of data bits by replacing said successive n-bit groups with respective ones from an ensemble of m-bit data words, each said m-bit data word having at least one associated valid n-bit code word, where n is greater than m, said apparatus comprising:
- means for determining a Hamming distance between a current n-bit group of said input digital signal and each of said valid n-bit code words;
- means for replacing said current n-bit group with an m-bit data word from said ensemble of m-bit data words for which said Hamming distance between a valid n-bit code word associated with said m-bit data word and said current n-bit group is the lowest;
- means for detecting whether two or more of said valid n-bit code words have said lowest Hamming distance from said current n-bit group;
- means, responsive to a detection that two or more of said valid n-bit code words have said lowest Hamming distance from said current n-bit group, for detecting whether said lowest Hamming distance is equal to one and, if so, for replacing said current n-bit group with an m-bit data word associated with one of said two or more valid n-bit code words having said lowest Hamming distance from said current n-bit group;
- means, responsive to a detection that said lowest Hamming distance is not equal to one, for detecting a bit separation of bit differences between said current n-bit group and said two or more valid n-bit code words;
- and
- means for replacing said current n-bit group with an m-bit data word for which said bit separation between a valid n-bit code word associated with said m-bit data word and said current group is the lowest.
Apparatus for decoding an input digital signal comprising successive n-bit groups of data bits by replacing said successive n-bit groups with respective ones from an ensemble of m-bit data words, each said m-bit data word having at least one associated valid n-bit code word, where n is greater than m, said apparatus comprising:
- means for determining a Hamming distance between a current n-bit group of said input digital signal and each of said valid n-bit code words;
- means for detecting whether two or more of said valid n-bit code words each have the lowest Hamming distance from said current n-bit group and for determining whether said lowest Hamming distance is more than one;
- means, responsive to a determination that said lowest Hamming distance is more than one, for detecting bit separations between a predetermined type of bits in each respective group of bits formed from said current n-bit group and each of said two or more valid n-bit code words;
- and
- means for replacing said current n-bit group with an m-bit data word having a lowest value of said bit separation.
Dependencies are inferred from the claim text.