Low complexity error correction using cyclic redundancy check (CRC)
View Patent ↗Communications between at communication devices, sometimes including at least one redundant transmission from a transmitter to a receiver, undergo low complexity error correction. CRC may be employed in conjunction with using any desired type of ECC or using uncoded modulation. Based on CRC determined bit-errors, as few as a singular syndrome associated with a singular bit-error or a linear combination of syndromes associated with two or more singular bit-errors within two or more received signal sequences are employed to perform error correction of the received signal. Real time combinations of multiple syndromes associated with respective single bit-errors (that may themselves be calculated off-line) are employed in accordance with error correction. In addition to CRC, any ECC may be employed including convolutional code, RS code, turbo code, TCM code, TTCM code, LDPC code, or BCH code.
1. An apparatus, comprising:
a bit error identification circuitry to determine at least one bit-error location within a first signal sequence using at least one of the first signal sequence and a second signal sequence;
a permutation selection circuitry, coupled to the bit error identification circuitry, to determine, based on the at least one bit-error location, at least one permutation syndrome corresponding to a cyclic redundancy check (CRC) remainder of the first signal sequence; and
a processing circuitry, coupled to the permutation selection circuitry, to generate a corrected signal sequence using the at least one of the first signal sequence and the second signal sequence.
2. The apparatus of claim 1 , wherein the bit error identification circuitry comprising:
an XOR mapping circuitry to perform XOR processing of individual bits within each of the first signal sequence and the second signal sequence to determine the at least one bit-error location.
3. The apparatus of claim 1 , wherein:
the bit error identification circuitry to employ soft information corresponding to bits within at least one of the first signal sequence and the second signal sequence to determine the at least one bit-error location.
4. The apparatus of claim 1 , wherein:
the second signal sequence being a retransmission of the first signal sequence.
5. The apparatus of claim 1 , wherein:
the at least one permutation syndrome being a linear combination of a first syndrome corresponding to first single bit error within first signal sequence and a second syndrome corresponding to second single bit error within first signal sequence.
6. The apparatus of claim 5 , further comprising:
a memory, coupled to the processing circuitry, to store a plurality of syndromes respectively differentiated in accordance with gray coding; and wherein:
the permutation selection circuitry to select the first syndrome and the second syndrome from the plurality of syndromes.
7. The apparatus of claim 1 , wherein:
the processing circuitry to flip at least one bit within the at least one of the first signal sequence and the second signal sequence in accordance with generating the corrected signal sequence.
8. The apparatus of claim 1 , wherein:
each of the first signal sequence and the second signal sequence respectively including error correction code (ECC) encoded bits therein.
9. The apparatus of claim 8 , wherein:
the ECC being a convolutional code, a Reed-Solomon (RS) code, a turbo code, a trellis coded modulation (TCM) code, a turbo trellis coded modulation (TTCM) code, a low density parity check (LDPC) code, or a BCH (Bose and Ray-Chaudhuri, and Hocquenghem) code.
10. The apparatus of claim 1 , wherein:
a decoder circuitry, coupled to the processing circuitry, to decode the at least one of the first signal sequence and the second signal sequence to generate estimates of error correction code (ECC) encoded bits therein.
11. The apparatus of claim 1 , wherein:
the apparatus being a communication device; and
the communication device being operable to be implemented within at least one of a satellite communication system, a wireless communication system, a wired communication system, and a fiber-optic communication system.
12. An apparatus, comprising:
an input to receive a first signal sequence and a second signal sequence from a communication channel, wherein the second signal sequence corresponding to a redundant transmission of the first signal sequence;
a bit error identification circuitry to determine at least one bit-error location within the first signal sequence in accordance with XOR mapping processing of the first signal sequence and the second signal sequence;
a permutation selection circuitry, coupled to the bit error identification circuitry, for determining, based on the at least one bit-error location, at least one permutation syndrome corresponding to a cyclic redundancy check (CRC) remainder of the first signal sequence; and
a processing circuitry, coupled to the permutation selection circuitry, to generate a corrected signal sequence using the at least one of the first signal sequence and the second signal sequence.
13. The apparatus of claim 12 , wherein:
the at least one permutation syndrome being a linear combination of a first syndrome corresponding to first single bit error within first signal sequence and a second syndrome corresponding to second single bit error within first signal sequence.
14. The apparatus of claim 13 , further comprising:
a memory, coupled to the processing circuitry, to store a plurality of syndromes respectively differentiated in accordance with gray coding; and wherein:
the permutation selection circuitry to select the first syndrome and the second syndrome from the plurality of syndromes.
15. The apparatus of claim 12 , wherein:
the processing circuitry to flip at least one bit within the at least one of the first signal sequence and the second signal sequence in accordance with generating the corrected signal sequence.
16. The apparatus of claim 12 , wherein:
each of the first signal sequence and the second signal sequence respectively including error correction code (ECC) encoded bits therein.
17. The apparatus of claim 16 , wherein:
the ECC being a convolutional code, a Reed-Solomon (RS) code, a turbo code, a trellis coded modulation (TCM) code, a turbo trellis coded modulation (TTCM) code, a low density parity check (LDPC) code, or a BCH (Bose and Ray-Chaudhuri, and Hocquenghem) code.
18. The apparatus of claim 12 , wherein:
a decoder circuitry, coupled to the processing circuitry, to decode the at least one of the first signal sequence and the second signal sequence to generate estimates of error correction code (ECC) encoded bits therein.
19. A method for operating a communication device, the method comprising:
receiving a first signal sequence from a communication channel;
determining at least one bit-error location within the first signal sequence using at least one of the first signal sequence and a second signal sequence;
determining, based on the at least one bit-error location, at least one permutation syndrome corresponding to a cyclic redundancy check (CRC) remainder of the first signal sequence; and
generating a corrected signal sequence using the at least one of the first signal sequence and the second signal sequence.
20. The method of claim 19 , further comprising:
performing XOR processing of individual bits within each of the first signal sequence and the second signal sequence for determining the at least one bit-error location.
21. The method of claim 19 , further comprising:
employing soft information corresponding to bits within at least one of the first signal sequence and the second signal sequence for determining the at least one bit-error location.
22. The method of claim 19 , wherein:
the second signal sequence being a retransmission of the first signal sequence.
23. The method of claim 19 , wherein:
the at least one permutation syndrome being a linear combination of a first syndrome corresponding to first single bit error within first signal sequence and a second syndrome corresponding to second single bit error within first signal sequence.
24. The method of claim 23 , further comprising:
storing a plurality of syndromes respectively differentiated in accordance with gray coding within a memory of the communication device; and
selecting the first syndrome and the second syndrome from the plurality of syndromes.
25. The method of claim 19 , further comprising:
flipping at least one bit within the at least one of the first signal sequence and the second signal sequence in accordance with generating the corrected signal sequence.
26. The method of claim 19 , wherein:
each of the first signal sequence and the second signal sequence respectively including error correction code (ECC) encoded bits therein.
27. The method of claim 26 , wherein:
the ECC being a convolutional code, a Reed-Solomon (RS) code, a turbo code, a trellis coded modulation (TCM) code, a turbo trellis coded modulation (TTCM) code, a low density parity check (LDPC) code, or a BCH (Bose and Ray-Chaudhuri, and Hocquenghem) code.
28. The method of claim 19 , further comprising:
decoding the at least one of the first signal sequence and the second signal sequence thereby generating estimates of error correction code (ECC) encoded bits therein.
29. The method of claim 19 , wherein:
the communication device being operable to be implemented within at least one of a satellite communication system, a wireless communication system, a wired communication system, and a fiber-optic communication system.