Method and apparatus for digital communication with error encoding according to division of data in classes

摘要

An encoder is described which encodes digital signals by first dividing them into their importance to data (eg speech). Error detection encoding is carried out for each class. A decoder for decoding data encoded by the disclosed encoder, detects errors in respective classes of signals. The existence of errors in the class and the respective importance of the classes can be combined to give an overall modification of the level of error detected in a signal.