Detecting accurrences of redundant digital codewords
AssigneeRockwell International Corporation
InventorsJames H. Brown, Johannes Grande
Life of this patent
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Abstract
Detection of repeatedly transmitted redundant digital codewords is provided by checking corresponding bi-positions for consecutive n bit codewords, counting the number of ones and zeros for each bit-position. When there is at least a preselected threshold J.sub.M of equal bit values for each of the n bit-positions of the codewords, in M or less consecutive codewords, the detection process is complete.
Claims11
A method for detecting redundant digital codewords repeatedly transmitted over a digital transmission system, comprising determining the values of bits in corresponding bit-positions of consecutive n bit codewords and providing, in response to said values, a codeword detected signal when there are at least J.sub.M equal bit values for each of the n bit-positions of the codewords, in M consecutive codewords, where J.sub.M is a preselectable threshold less than M.
A method for detecting redundant digital codewords repeatedly transmitted over a digital transmission system, comprising:
- reading a given bit of each of a plurality of the M codewords;
- counting, for plural bit values, the number of said bits assuming each bit value;
- comparing said count against a predetermined threshold J.sub.M and outputting a bit value signal and a bit detected signal when said count equals or exceeds J.sub.M ;
- and
- repeating the above sequence of steps for each of the remaining bit-positions in the codewords.
A method for detecting redundant digital codewords repeatedly transmitted over a digital transmission system, comprising:
- storing M codewords in a memory having a bit capacity of at least n.times.M, where n is the number of bits in a codeword;
- reading from said memory a plurality of bits with memory locations spaced every n.sup.th bit, starting with a given bit;
- counting ones and zeros in the bits read;
- comparing the counted number of ones and zeros against a predetermined threshold J.sub.M, and outputting a bit value signal and a bit detected signal when either count equals or exceeds J.sub.M ;
- storing said bit value signal in a memory having a capacity of at least n bits;
- storing said bit detected signal in a memory having a capacity of at least n bits;
- repeating the preceding five steps for each of the remaining bit-positions in the codewords;
- providing a codeword detected signal from said bit detected signal memory if the latter reaches a content of n bits;
- and
- providing a codeword value signal from said bit value signal memory.
A digital codeword detector for detecting redundant codewords repeatedly transmitted over a digital transmission system, comprising:
- a first memory having a bit capacity of at least n.times.M for storing M codewords, each n bits long;
- means for reading from said first memory a given bit-position of each of a plurality of M codewords;
- count and compare means for counting, for plural bit values, the number of said bit-positions read which contain each bit value and comparing said count against a predetermined threshold J.sub.M, and outputting a bit value signal and a bit detected signal when said count equals or exceeds J.sub.M ;
- a second memory, having a capacity of at least n bits and responsive to said count and compare means, for storing said bit detected signal, and outputting a codeword detected signal if its content reaches n bits;
- and
- a third memory, having a capacity of at least n bits and responsive to said count and compare means, for storing said bit value signal, and outputting a codeword value signal.
Dependencies are inferred from the claim text.