Talk:Error detection and correction

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Information theory and error detection and correction

The following paragraph is slightly misleading:

"Information theory tells us that whatever be the probability of error in transmission or storage, it is possible to construct error correction codes in which the likelihood of failure is arbitrarily low. It gives a bound on the efficiency that such schemes can achieve."

The problem with this is that in case the error is "perfectly random", e.g. for a bit channel, if the error probability per bit is >exactly< 1/2 and bit errors are independant of each other, then there is no code that can preserve >any< information in the channel, e.g. whatever the sender put into the channel, the receiver would only get perfectly random "noise".

Higher bit error probabilities are ok again, because inverting the arriving signal can then be used to invert (1-p) the error probability p to less than 1/2.

No error correction scheme can work if the output of the channel is independent of its input - all error, no data. As the error rate increases, the amount of additional ECC information necessary increases until we get to the extreme for a totally unreliable channel where all bandwidth must be devoted to ECC and no data gets through. I believe the current version of the text at Error detection and correction § Forward error correction correctly implies this. ~Kvng (talk) 23:47, 16 July 2022 (UTC)

EDAC (error detection and correction)

I usually hear the phrase "error detection and correction" (EDAC) rather than "error correction and detection". What does Google say? --DavidCary 00:42, 21 September 2005 (UTC)

Article we renamed at one point perhaps in appreciation of this. ~Kvng (talk) 23:54, 16 July 2022 (UTC)

History of Error Detection and Jewish Scribes Real?

The following discussion is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

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The history paragraph appears speculative and original research. Yes, the scribes were meticulous with copying over texts, and yes, it is known that the had the numerical Masorah from counting the letters. But, is there any evidence that Masorah was used to check whether the text was accurately copied? The Jewish Encyclopedia's discussion the Numerical Masorah does not mention this use of it at all: http://www.jewishencyclopedia.com/articles/10465-masorah Jb12345678910111213 (talk) 18:15, 8 August 2016 (UTC)

The discussion above is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

History

The history section says Hamming developed codes in 1947 and they were published by Shannon in 1948. Hamming code says the code was developed in 1950. Are we talking about the same code here? ~Kvng (talk) 14:24, 18 May 2018 (UTC)

As I understand it, Hamming started thinking about error correcting codes in 1947, came up with the H(7,4) code in 1948, and published it in 1950. There is a parametric series of Hamming codes, but sometimes the most well-known of them, the H(7,4) code, is thought is as the Hamming code. Unfortunately, that is from personal recollection and a little Googling. I don't have a solid secondary source available that explains this. --Mark viking (talk) 18:12, 18 May 2018 (UTC)

So Shannon published a preview of Hamming's work? We should change developed to published in Hamming code. ~Kvng (talk) 13:00, 21 May 2018 (UTC)