Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
176 words
A method of transmitting digital television signals comprising the steps of: forming the data words representing a digital television signal into successive data segments, each said data segment comprising a plurality of data blocks, each said data block comprising a plurality of data sub-blocks, and each said data sub-block comprising a plurality of said data words; generating a respective first error correcting code for each said data sub-block for use in correcting at least one bit which may be in error in said data sub-block; generating a respective error detecting code for each said data block for use in detecting whether said first error correcting code has been successful in correcting all errors in the respective said data block; generating a respective second error correcting code for each said data segment for use in correcting at least one data word which may be in error in said data segment; and combining said first and second error correcting codes and said error detecting code into the respective said data segments for transmission of said digital television signal.
Claim 2
Independent Claim
176 words
A method of transmitting digital television signals comprising the steps of: forming the data words representing a digital television signal into successive data segments, each said data segment comprising a plurality of data blocks, each said data block comprising a plurality of data sub-blocks, and each said data sub-block comprising a plurality of said data words; generating a respective first error correcting code for each said data sub-block for use in correcting at least one bit which may be in error in said data sub-block; generating a respective error detecting code for each said data block for use in detecting whether said first error correcting code has been successful in correcting all errors in the respective said data block; generating a respective second error correcting code for each said data segment for use in correcting at least one data word which may be in error in said data segment; and combining said first and second error correcting codes and said error detecting code into the respective said data segments for transmission of said digital television signal.
Claim 3
Dependent Claim
64 words
A method according to claim 1 wherein said first error correcting code is assembled with and forms part of the respective said data sub-block for transmission, said error detecting code is assembled with and forms part of the respective said data block for transmission, and said second error correcting code is assembled with and forms part of the respective said data segment for transmission.
Claim 4
Dependent Claim
50 words
A method according to claim 2 wherein the format of said second error correcting code is the same as that of the data words in a said data block and said second error correcting code block contains respective said first error correcting codes and a respective said error detecting code.
Claim 5
Dependent Claim
21 words
A method according to claim 1, claim 2 or claim 3 wherein said first error correcting code is a Hamming code.
Claim 6
Dependent Claim
19 words
A method according to claim 4 wherein said Hamming code is a modified form such as a b-adjacent code.
Claim 7
Independent Claim
21 words
A method according to any one of the preceding claims wherein said error detecting code is a cyclic redundancy check code.
Claim 8
Independent Claim
21 words
A method according to any one of the preceding claims wherein said second error detecting code is a parity check code.
Claim 9
Dependent Claim
22 words
A method according to claim 1, claim 2 or claim 3 wherein said error detecting code additionally has an error correction capability.
Claim 10
Dependent Claim
202 words
An error correction encoder for digital television signals, the encoder comprising: means for forming the data words representing a digital television signal into successive data segments, each said data segment comprising a plurality of data blocks, each said data block comprising a plurality of data sub-blocks, and each said data sub-block comprising a plurality of said data words; first error correcting code means (3) for generating a respective first error correcting code for each said data sub-block for use in correcting at least one bit which may be in error in said data sub-block; error detecting code means (4) for generating a respective error detecting code for each said data block for use in detecting whether said first error correcting code has been successful in correcting all errors in the respective said data block; second error correcting code means (6, 7) for generating a respective second error correcting code for each said data segment for use in correcting at least one data word which may be in error in said data segment; and means (5) for combining said first and second error correcting codes and said error detecting code into the respective said data segments for transmission of said digital television signal.
Claim 11
Dependent Claim
202 words
An error correction encoder for digital television signals, the encoder comprising: means for forming the data words representing a digital television signal into successive data segments, each said data segment comprising a plurality of data blocks, each said data block comprising a plurality of data sub-blocks, and each said data sub-block comprising a plurality of said data words; first error correcting code means (3) for generating a respective first error correcting code for each said data sub-block for use in correcting at least one bit which may be in error in said data sub-block; error detecting code means (4) for generating a respective error detecting code for each said data block for use in detecting whether said first error correcting code has been successful in correcting all errors in the respective said data block; second error correcting code means (6, 7) for generating a respective second error correcting code for each said data segment for use in correcting at least one data word which may be in error in said data segment; and means (5) for combining said first and second error correcting codes and said error detecting code into the respective said data segments for transmission of said digital television signal.
Claim 12
Dependent Claim
147 words
An error correction encoder according to claim 9 in combination with an error correction decoder comprising: means (20) for receiving said transmitted digital television signal; first means (22) operative in dependence on the respective said first error correcting code for correcting at least one bit error in a said data sub-block and for flagging that a correction has been attempted in a said data sub-block; second means (24) operative in dependence on said error detecting code for detecting any errors remaining in the respective data block after operation of said first means (22), for flagging said remaining errors, and, if no errors remain, for cancelling flags set by said first means; and third means (26 to 42) operative in dependence on said second error correcting code for correcting at least one data word error remaining in a said data segment, after operation of said second means (24).