Data signal handling arrangements

Claim 1

A method of data handling for correcting errors arising in a transmission channel in a system in which double adjacent errors are predominant, which comprises the steps of: a. transmitting a succession of K data bits as a codeword of N bits B 1 to B n where N > K and where the bits B 1 to B n are related to bits P 1 to P n of a codeword of any code capable of correcting errors occurring at random by the fact that each ith term P i is equal to the cumulative sum modulo 2 of the terms B 1 to B i and that the last bit P n of each codeword P 1 to P n has the same value, i.e., 0 or 1; b. receiving the transmitted codeword and recovering therefrom the codeword P 1 to P n or its inverse by cumulatively summing the received bits B 1 to B n ; c. correcting for double adjacent errors introduced by the transmission of step (a) by decoding said recovered codeword according to said code capable of correcting errors occurring at random to produce a corrected codeword B 1 to B n ; and d. recovering the K data bits from the corrected codeword.

Claim 2

A method of data handling for correcting errors arising in a transmission channel in a system in which double adjacent errors are predominant, which comprises the steps of: a. transmitting a succession of K data bits as a codeword of N bits B 1 to B n where N > K and where the bits B 1 to B n are related to bits P 1 to P n of a codeword of any code capable of correcting errors occurring at random by the fact that each ith term P i is equal to the cumulative sum modulo 2 of the terms B 1 to B i and that the last bit P n of each codeword P 1 to P n has the same value, i.e., 0 or 1; b. receiving the transmitted codeword and recovering therefrom the codeword P 1 to P n or its inverse by cumulatively summing the received bits B 1 to B n ; c. correcting for double adjacent errors introduced by the transmission of step (a) by decoding said recovered codeword according to said code capable of correcting errors occurring at random to produce a corrected codeword B 1 to B n ; and d. recovering the K data bits from the corrected codeword.

Claim 5

A method of data handling for correcting errors arising in a transmission channel in a system in which double adjacent errors are predominant, which comprises the steps of: a. transmitting a codeword of N bits B 1 to B n to represent a plurality K of data bits where N > K and where there are N - K parity bits, the bits B 1 to B n of the transmitted codeword being related to the bits P 1 to P n of a codeword of any code capable of correcting errors occurring at random by the fact that each i th term P i is equal to the cumulative sum modulo 2 of the terms B 1 to B i and that the last bit P n of any codeword P 1 to P n has the same value; b. receiving the transmitted codeword and checking the parity thereof; c. correcting single errors in the K data bits of the received codeword to provide a corrected data bit word B' 1 to B' k ; d. recovering the codeword P 1 to P n or its inverse corresponding to the received codeword B 1 to B n and decoding the recovered codeword according to said code to provide a corrected data bit word B" 1 to B" k ; and e. selecting one of the corrected data bit words B' 1 to B' k and B" 1 to B" k according to the parity check of step (b).

Claim 6

A method of data handling for correcting errors arising in a transmission channel in a system in which double adjacent errors are predominant, which comprises the steps of: a. transmitting a codeword of N bits B 1 to B n to represent a plurality K of data bits where N > K and where there are N - K parity bits, the bits B 1 to B n of the transmitted codeword being related to the bits P 1 to P n of a codeword of any code capable of correcting errors occurring at random by the fact that each i th term P i is equal to the cumulative sum modulo 2 of the terms B 1 to B i and that the last bit P n of any codeword P 1 to P n has the same value; b. receiving the transmitted codeword and checking the parity thereof; c. correcting single errors in the K data bits of the received codeword to provide a corrected data bit word B' 1 to B' k ; d. recovering the codeword P 1 to P n or its inverse corresponding to the received codeword B 1 to B n and decoding the recovered codeword according to said code to provide a corrected data bit word B" 1 to B" k ; and e. selecting one of the corrected data bit words B' 1 to B' k and B" 1 to B" k according to the parity check of step (b).

Claim 10

A method of data handling for correcting errors arising in a transmission channel in a system in which double adjacent errors are predominant, which comprises the steps of: a. encoding successive sets of K data bits as successive first codewords of N bits containing N - K parity bits; b. transmitting said successive codewords by delta phase shift keying modulation to form second codewords of an error correcting code capable of correcting errors occurring at random and in which the last bit of each second codeword is of the same value; c. receiving the transmitted codewords to recover the first codewords, and checking the parity thereof; d. generating said second codewords from the recovered first codewords and decoding them according to said code to produce a corrected sequence of said K data bits when the parity check of step (c) indicates that double adjacent errors have occurred during transmission.

Claim 11

A method of data handling for correcting errors arising in a transmission channel in a system in which double adjacent errors are predominant, which comprises the steps of: a. encoding successive sets of K data bits as successive first codewords of N bits containing N - K parity bits; b. transmitting said successive codewords by delta phase shift keying modulation to form second codewords of an error correcting code capable of correcting errors occurring at random and in which the last bit of each second codeword is of the same value; c. receiving the transmitted codewords to recover the first codewords, and checking the parity thereof; d. generating said second codewords from the recovered first codewords and decoding them according to said code to produce a corrected sequence of said K data bits when the parity check of step (c) indicates that double adjacent errors have occurred during transmission.