5 ms·
One important stage of error correction is spreading, that use a pseudo-random function to 'spread' the damaged data over several blocks that can be then comple
by aortega 4y ago
One important stage of error correction is spreading, that use a pseudo-random function to 'spread' the damaged data over several blocks that can be then completely recovered, instead of concentrating the damage in a single block (like often happen in erasures) that cannot be recovered.
- userbinator 4y agoOptical media like CDs and DVDs use a similar interleaving scheme, allowing for large amounts of errors to be corrected; in fact, even during normal operation with what appears to be a completely clean and perfect disc and drive, read errors are always occurring but corrected silently so there is no loss of data: https://en.wikipedia.org/wiki/Cross-interleaved_Reed%E2%80%93Solomon_coding https://en.wikipedia.org/wiki/Cross-interleaved_Reed%E2%80%9... https://en.wikipedia.org/wiki/Optical_disc#Surface_error_scanning https://en.wikipedia.org/wiki/Optical_disc#Surface_error_sca...
- nayuki 4y agoBy spreading, I think you're referring to interleaving https://en.wikipedia.org/wiki/Burst_error-correcting_code#Interleaved_codes https://en.wikipedia.org/wiki/Burst_error-correcting_code#In... , which doesn't need randomness. Pseudo-random scrambling is used in places like https://en.wikipedia.org/wiki/64b/66b_encoding https://en.wikipedia.org/wiki/64b/66b_encoding to reduce the chances of many consecutive 0s or 1s which could cause clock desynchronization between the sender and receiver.
- aortega 4y ago>By spreading, I think you're referring to interleaving https://en.wikipedia.org/wiki/Burst_error-correcting_code#In https://en.wikipedia.org/wiki/Burst_error-correcting_code#In... , which doesn't need randomness. I stand corrected!
- joshspankit 4y ago> I stand corrected! Heh