- BCJR algorithm
The BCJR algorithm is an algorithm for
maximum a posteriori decoding oferror correcting code s defined on trellises (principallyconvolutional code s). The algorithm is named after its inventers: Bahl, Cocke, Jelinek and Raviv L.Bahl, J.Cocke, F.Jelinek, and J.Raviv, "Optimal Decoding of Linear Codes for minimizing symbol error rate", IEEE Transactions on Information Theory, vol. IT-20(2), pp.284-287, March 1974.] . This algorithm is critical to modern iteratively-decoded error-correcting codes includingturbo code s andlow-density parity-check code s.Variations
SGBT BCJR
Berrou, Glavieux and Thitimajshima Simplification [Sichun Wang and François Patenaude, "A Systematic Approach to Modified BCJR MAP Algorithms for Convolutional Codes," "EURASIP Journal on Applied Signal Processing", vol. 2006, Article ID 95360, 15 pages, 2006. doi:10.1155/ASP/2006/95360] .
Log-Map BCJR
Max-Log-Map BCJR
ee also
*
Forward-backward algorithm
* Maximum a posteriori (MAP) estimationReferences
External links
* [http://www.inference.phy.cam.ac.uk/mackay/itila/ The on-line textbook: Information Theory, Inference, and Learning Algorithms] , by
David J.C. MacKay , discusses the BCJR algorithm in chapter 25.
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