Soft-output BEAST decoding with application to product Codes

Summary, in English

A Bidirectional Efficient Algorithm for Searching code Trees (BEAST) is proposed for efficient soft-output decoding of block codes and concatenated block codes. BEAST operates on trees corresponding to the minimal trellis of a block code and finds a list of the most probable codewords. The complexity of the BEAST search is significantly lower than the complexity of trellis-based algorithms, such as the Viterbi algorithm and its list-generalizations. The outputs of BEAST, a list of best codewords and their metrics, are used to obtain approximate a posteriori reliabilities of the transmitted symbols, yielding a soft-input soft-output (SISO) symbol decoder referred to as the BEAST-APP decoder. This decoder is employed as a component decoder in iterative schemes for decoding of product and incomplete product codes. Its performance and convergence behavior are investigated using EXIT charts and compared to existing

decoding schemes. It is shown that the BEAST-APP decoder achieves performances close to the BCJR decoder with a substantially lower computational complexity.

• Author: Maja Loncar; Rolf Johannesson; Irina Bocharova; Boris Kudryashov
• Department/s: Department of Electrical and Information Technology
• Publishing year: 2008
• Language: English
• Pages: 1036-1049
• Publication/Series: IEEE Transactions on Information Theory
• Volume: 54
• Issue: 3
• Full text: - 389 kB; Download statistics
• Links: http://dx.doi.org/10.1109/TIT.2007.915971
• Document type: Journal article
• Publisher: IEEE - Institute of Electrical and Electronics Engineers Inc.
• Topic: Electrical Engineering, Electronic Engineering, Information Engineering
• Keywords: block turbo codes; list decoding; product codes; BEAST; soft-input soft-output (SISO) decoding
• Status: Published
• Research group: Information Theory
• ISBN/ISSN/Other: ISSN: 0018-9448