Digital Television Error Correction without Overhead Bits
|Author(s):||A. A. Goldberg ; J. P. Rossi|
|Publisher:||Society of Motion Picture and Television Engineers|
|Publication Date:||1 February 1981|
|Conference Location:||San Francisco, CA, USA|
|Conference Date:||6 February 1981|
|Page(s):||80 - 88|
Transmission, storage and processing of PCM digital television signals in noisy channels subjects the digital signal to uncertainties, and causes bit errors. These appear as random bright and dark noise specks in the picture. The usual way of dealing with errors is by adding parity bits to identify and correct the errors. Many error correcting codes utilizing interlinked parity bits have been developed for this purpose and require overhead bits to carry redundant information. Whenever there is a statistical probability of excessive errors being generated, the television system has had to carry the burden of these overhead bits in order to insure satisfactory picture quality. The penalty is a higher total bit rate. There may be situations where bit errors have occurred in a prior section of the television chain outside our control. If the signal lacks parity coding, then there will be no way to reduce the bit error rate using parity techniques.