Turbo code: Difference between revisions

Revision as of 08:02, 22 April 2019

Revision as of 08:03, 22 April 2019

Line 10:

The fundamental patent application for turbo codes was filed on April 23, 1991. The patent application lists [[Claude Berrou]] as the sole inventor of turbo codes. The patent filing resulted in several patents including [https://www.google.com/patents/US5446747 US Patent 5,446,747], which expired August 29, 2013.

The first public paper on turbo codes was "''Near Shannon Limit Error-correcting Coding and Decoding: Turbo-codes''".<ref>{{Citation|url=https://www.researchgate.net/publication/3604275_Near_Shannon_limit_error-correcting_coding_and_decoding_Turbo-codes_1|first=Claude|first2=Alain|first3=Punya|last=Berrou|last2=Glavieux|last3=Thitimajshima|title=Near Shannon Limit Error – Correcting|accessdate=11 February 2010}}</ref> This paper was published 1993 in the Proceedings of IEEE International Communications Conference. The 1993 paper was formed from three separate submissions that were combined due to space constraints. The merger caused the paper to list three authors: [[Claude Berrou|Berrou]], [[Alain Glavieux|Glavieux]], and [[Punya Thitimajshima|Thitimajshima]] (from Télécom Bretagne, former [[École Nationale Supérieure des Télécommunications de Bretagne|ENST Bretagne]], France). However, it is clear from the original patent filing that Claude Berrou is the sole inventor of turbo codes and that the other authors of the paper contributed material other than the core concepts.

Turbo codes were so revolutionary at the time of their introduction that many experts in the field of coding did not believe the reported results. When the performance was confirmed a small revolution in the world of coding took place that led to the investigation of many other types of iterative signal processing.

Line 16:

The first class of turbo code was the parallel concatenated convolutional code (PCCC). Since the introduction of the original parallel turbo codes in 1993, many other classes of turbo code have been discovered, including serial versions [[serial concatenated convolutional codes]] and [[repeat-accumulate code]]s. Iterative turbo decoding methods have also been applied to more conventional FEC systems, including Reed-Solomon corrected convolutional codes, although these systems are too complex for practical implementations of iterative decoders. Turbo equalization also flowed from the concept of turbo coding.

In addition to turbo codes, Claude Berrou also invented recursive systematic convolutional (RSC) codes, which are used in the example implementation of turbo codes described in the patent. Turbo Codes that use RSC codes seem to perform better than Turbo codes that do not use RSC codes.

Prior to turbo codes, the best constructions were serial [[concatenated code]]s based on an outer [[Reed-Solomon error correction]] code combined with an inner [[Viterbi algorithm|Viterbi-decoded]] short constraint length [[convolutional code]], also known as RSV codes.