Error correction coding across multiple channels in content distribution systems
Error correction coding across multiple channels is provided in multi-channel transmission systems. Specifically, redundancy is provided by selecting a portion of original data from each of a plurality of original channels, performing at least one encoding operation using the portions of original data to produce at least one portion of redundancy data, including the portion of redundancy data in at least one redundancy channel, and transmitting the redundancy channel along with the original channels. Error correction is achieved by receiving at least one redundancy channel and a plurality of original channels, selecting a portion of redundancy data from the redundancy channel, selecting a portion of original data from each of the original channels, and performing at least one decoding operation using the portion of redundancy data and the portions of original data to correct at least one error in the portions of original data.
1. A method comprising:
receiving a redundancy RF channel and a plurality of original RF channels over a communication medium;
demodulating the redundancy RF channel resulting in a redundancy data sequence and demodulating the plurality of original RF channels resulting in a plurality of original data sequences;
sampling a symbol from the redundancy data sequence;
sampling a symbol from each of the plurality of original data sequences; and
correcting an error in one of the plurality of original data sequences using the sampled symbol from the redundancy data sequence and the sampled symbol from each of the plurality of original data sequences, wherein:
each of the plurality of original data sequences is associated with a different one of the plurality of original RF channels and represents a different independent video or audio data sequence, and
the sampling a symbol from each of the plurality of original data sequences and a symbol from the one redundancy data sequence includes aligning the plurality of original data sequences and the redundancy data sequence.
2. The method of claim 1 , wherein the correcting the error further comprises
processing error detection data generated during the process of demodulating the plurality of original RF channels.
3. The method of claim 2 , wherein the error detection data is generated based on an in-channel error correction decoding process performed for a particular one of the plurality of original RF channels in which the one of the plurality of original data sequences is associated.
4. The method of claim 3 , wherein the error detection data comprises an indication of the error in the one of the plurality of original data sequences.
5. The method of claim 3 , wherein the error detection data comprises a location of the error in the one of the plurality of original data sequences.
6. The method of claim 3 , wherein the error detection data comprises a time at which the error in the one of the plurality of original data sequences occurs.
7. The method of claim 1 , wherein the correcting the error further comprises performing a parity bit calculation.
8. The method of claim 1 , wherein the correcting the error further comprises performing a cross-channel decoding operation using a block code.
9. The method of claim 8 , wherein the block code is a Reed-Solomon code.
10. The method of claim 1 , wherein the communication medium is a cable-based medium or a satellite based medium.
11. The method of claim 1 , wherein a content stream corresponding to each of the original data sequences includes an audio signal and a video signal.
12. A system, comprising:
a receiver configured to receive a redundancy RF channel and a plurality of original RF channels over a communication medium;
a demodulator configured to demodulate the redundancy RF channel resulting in a redundancy data sequence and demodulate the plurality of original RF channels resulting in a plurality of original data sequences; and
a cross-channel error correction decoder configured to sample a symbol from the redundancy data sequence, to sample a symbol from each of the plurality of original data sequences, and to correct an error in one of the plurality of original data sequences using the sampled symbol from the redundancy data sequence and the sampled symbol from each of the plurality of original data sequences, wherein:
each of the plurality of original data sequences is associated with a different one of the plurality of original RF channels and represents a different independent video or audio data sequence, and
to sample a symbol from each of the plurality of original data sequences and the redundancy data sequence, the cross-channel error correction decoder is configured to align the plurality of original data sequences and the redundancy data sequence.
13. The system of claim 12 , wherein the a cross-channel error correction decoder is further configured to process error detection data generated by the demodulator.
14. The system of claim 13 , wherein the error detection data is generated based on an in-channel error correction decoding process performed for a particular one of the plurality of original RF channels in which the one of the plurality of original data sequences is associated.
15. The system of claim 14 , wherein the error detection data comprises an indication of the error in the one of the plurality of original data sequences.
16. The system of claim 14 , wherein the error detection data comprises a location of the error in the one of the plurality of original data sequences.
17. The system of claim 14 , wherein the error detection data comprises a time at which the error in the one of the plurality of original data sequences occurs.
18. The system of claim 12 , wherein the cross-channel error correction decoder is further configured to perform a parity bit calculation to correct the error in the one of the plurality of original data sequences.
19. The system of claim 12 , wherein the cross-channel error correction decoder is further configured to use a block code to correct the error in the one of the plurality of original data sequences.
20. A system, comprising:
a receiver configured to receive a redundancy RF channel and a plurality of original RF channels over a communication medium;
a demodulator configured to demodulate the redundancy RF channel resulting in a redundancy data sequence and demodulate the plurality of original RF channels resulting in a plurality of original data sequences, wherein each of the plurality of original data sequences is associated with a different one of the plurality of original RF channels and corresponds to a different video content stream; and
a cross-channel error correction decoder configured correct an error in one of the plurality of original data sequences using a symbol from the redundancy data sequence and a symbol from each of the plurality of original data sequences, wherein the cross-channel error correction decoder is configured to align the plurality of original data sequences and the redundancy data sequence.