Bose-Chaudhuri-Hocquenghem Code (BCH)

The BCH code (Bose-Chaudhuri-Hocquenghem code) is a code for error detection and error correction that works with cyclic block checking(CRC).

It is a variable length Multi Level Coding( MLC) with which up to 25% of the total bits can bechecked and corrected. Since the BCH code can only correct two errors, the errors are decoded relatively quickly using two equations with two unknowns for the position.

The BCH code can be used not only for binary signals, but also for multilevel signals with phase shift keying. The BCH code is used in telecommunications, for example in the control channels of cellular TDMA procedures in the USA and in the POCSAG code.