# 7.4 Advanced block coding

## Block code families

Hamming codes are in fact a subset of a more general code family called BCH (Bose-Chaudhuri-Hocquenghem) codes discovered in 1959 and 1960. Whereas the Hamming codes can only detect up to two errors or correct one, the general BCH code family can detect and correct any number of errors if the code word used is long enough. For example, the Hamming (4,7) code corrects only one error, while the BCH (64,127) code corrects 10 errors. For real error correcting power, the (11,1023) code can correct a staggering 255 errors but with a very high coding overhead indeed. This would be used where reliability of transmission is key and data throughput is less important. |

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