Soft decoding of CRC component codes
View Patent ↗Methods and devices are disclosed for encoding and decoding convolutional codes in a communication system. In various embodiments of the disclosure, a codeword comprises message data and parity data. A convolutional codeword is generated by multiplying the message data and the parity data with a convolutional polynomial. The convolutional codeword may be decoded by a convolutional code decoder that uses the convolutional polynomial and a maximum likelihood divisor to obtain a maximum likelihood message from the convolutional codeword.
1. A method of applying convolutional code decoding in a communication system, the method comprising:
receiving a noisy cyclic redundancy check (CRC) codeword;
performing, using a processing device, Viterbi decoding of said noisy cyclic redundancy check codeword configured for decoding a rate 1 convolutional code comprising a generator polynomial, thereby generating a decoded cyclic redundancy check codeword; and
processing said decoded cyclic redundancy check code word to generate a maximum likelihood message therefrom.
2. The method of claim 1 , wherein said cyclic redundancy check codeword is generated by multiplying a first divisor with a cyclic redundancy check generator polynomial.
3. The method of claim 2 , wherein said maximum likelihood message is obtained by reading the systematic portion of the CRC codeword.
4. A communication device comprising processing logic, wherein said processing logic is configured to:
receive a noisy cyclic redundancy check (CRC) codeword;
perform Viterbi decoding of said noisy cyclic redundancy check codeword configured for decoding a rate 1 convolutional code comprising a generator polynomial, thereby generating a decoded cyclic redundancy check codeword; and
process said decoded cyclic redundancy check code word to generate a maximum likelihood message therefrom.
5. The communication device of claim 4 , wherein said decoded cyclic redundancy check codeword is generated by multiplying a first divisor with a cyclic redundancy check generator polynomial.
6. The communication device of claim 4 , wherein said processing logic is configured to generate said maximum likelihood message by reading the systematic portion of the CRC codeword.
7. A method of recovering a transmitted message in a communication system, the method comprising:
receiving a noisy parity data stream corresponding to a composite convolutional codeword;
performing, using a processing device, decoding of said noisy parity data stream using a composite CRC/convolutional code comprising a CRC generator polynomial and a convolutional generator polynomial, thereby generating a decoded composite convolutional codeword; and
processing said decoded composite convolutional codeword to generate a maximum likelihood message therefrom.
8. The method of claim 7 , wherein said decoding of said recovered cyclic redundancy check codeword is implemented using Viterbi decoding.
9. The method of claim 7 , wherein said decoded composite convolutional codeword is generated by multiplying a first divisor with said CRC generator polynomial.
10. The method of claim 7 , wherein said maximum likelihood message is obtained by reading the systematic portion of the composite convolutional codeword.
11. A communication device comprising processing logic, wherein said processing logic is configured to:
receive a noisy parity data stream corresponding to a composite convolutional codeword;
perform decoding of said noisy parity data stream using a composite convolutional code CRC/convolutional code generator comprising a CRC generator polynomial and a convolutional generator polynomial, thereby generating a decoded composite convolutional codeword; and
process said decoded composite convolutional codeword to generate a maximum likelihood message therefrom.
12. The communication device of claim 11 , wherein said decoding of said recovered cyclic redundancy check codeword is implemented using Viterbi decoding.
13. The communication device of claim 11 , wherein said decoded composite convolutional codeword is generated by multiplying a first divisor with said CRC generator polynomial.
14. The communication device of claim 11 , wherein said maximum likelihood message is obtained by reading the systematic portion of the composite convolutional codeword.