Hamming Code
What is Hamming code? Hamming code is a category of error correcting codes that developed by Richard Hamming. Parity checking was already being used to detect errors in the calculations of the relay-based computers of the day, and Hamming realized that a more sophisticated pattern of parity checking allowed the correction of single errors along with the detection of double errors. These codes were originally designed with d min =3 , which mean that they can detect up to two errors or correct one single error. In simple parity check cannot correct the errors and can detect an odd number errors. First of all we need to know the relationship between n and k in a hamming code. We need to choose an integer m >3 . The values of n and k are then calculated from m as n = 2 m -1 and r = n-m . The number of check bits r = m . To calculate the number of redundancy bits use : 2 m ≥ n + m + 1 Example: If m=3, then n=7 and k=4. This is a hamming code C(7,4) with d min =3 . Fig