Extrinsic information transfer charts and constituent decoder for turbo coded communications

2015 ◽  
Author(s):  
Wenjun Yu ◽  
Jaeho Choi
Keyword(s):  
Information Transfer ◽  
Extrinsic Information

Application of Extrinsic Information Transfer Charts to Anticipate Turbo Code Behavior

2013 ◽  
pp. 97-104
Author(s):  
Izabella Lokshina
Keyword(s):  
Turbo Codes ◽  
Iterative Decoding ◽  
Information Transfer ◽  
Turbo Code ◽  
A Priori ◽  
Substantial Reduction ◽  
International Standards ◽  
Extrinsic Information ◽  
Exit Chart ◽  
Analysis Technique

This paper examines turbo codes that are currently introduced in many international standards, including the UMTS standard for third generation personal communications and the ETSI DVB-T standard for Terrestrial Digital Video Broadcasting. The convergence properties of the iterative decoding process associated with a given turbo-coding scheme are estimated using the analysis technique based on so-called extrinsic information transfer (EXIT) chart. This approach provides a possibility to anticipate the bit error rate (BER) of a turbo code system using only the EXIT chart. It is shown that EXIT charts are powerful tools to analyze and optimize the convergence behavior of iterative systems utilizing the turbo principle. The idea is to consider the associated SISO stages as information processors that map input a priori LLR’s onto output extrinsic LLR’s, the information content being obviously assumed to increase from input to output, and introduce them to the design of turbo systems without the reliance on extensive simulation. Compared with the other methods for generating EXIT functions, the suggested approach provides insight into the iterative behavior of linear turbo systems with substantial reduction in numerical complexity.

Application of Extrinsic Information Transfer Charts to Anticipate Turbo Code Behavior

2011 ◽  
Vol 3 (2) ◽  
pp. 31-37 ◽  
Author(s):  
Izabella Lokshina
Keyword(s):  
Turbo Codes ◽  
Iterative Decoding ◽  
Information Transfer ◽  
Turbo Code ◽  
A Priori ◽  
Substantial Reduction ◽  
International Standards ◽  
Extrinsic Information ◽  
Suggested Approach ◽  
Exit Chart

This paper examines turbo codes that are currently introduced in many international standards, including the UMTS standard for third generation personal communications and the ETSI DVB-T standard for Terrestrial Digital Video Broadcasting. The convergence properties of the iterative decoding process associated with a given turbo-coding scheme are estimated using the analysis technique based on so-called extrinsic information transfer (EXIT) chart. This approach provides a possibility to anticipate the bit error rate (BER) of a turbo code system using only the EXIT chart. It is shown that EXIT charts are powerful tools to analyze and optimize the convergence behavior of iterative systems utilizing the turbo principle. The idea is to consider the associated SISO stages as information processors that map input a priori LLR’s onto output extrinsic LLR’s, the information content being obviously assumed to increase from input to output, and introduce them to the design of turbo systems without the reliance on extensive simulation. Compared with the other methods for generating EXIT functions, the suggested approach provides insight into the iterative behavior of linear turbo systems with substantial reduction in numerical complexity.

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