Extrinsic information transfer functions: model and erasure channel properties

2004 ◽  
Vol 50 (11) ◽  
pp. 2657-2673 ◽  
Author(s):  
A. Ashikhmin ◽  
G. Kramer ◽  
S. ten Brink
Keyword(s):  
Information Transfer ◽  
Transfer Functions ◽  
Extrinsic Information ◽  
Erasure Channel ◽  
Channel Properties

Analysis of Turbo Code Behavior with Extrinsic Information Transfer Charts in High-Speed Wireless Data Services

2017 ◽  
Vol 9 (4) ◽  
pp. 26-36 ◽  
Author(s):  
Izabella Lokshina ◽  
Hua Zhong
Keyword(s):  
Turbo Codes ◽  
Communication Systems ◽  
Information Transfer ◽  
High Speed ◽  
Transfer Functions ◽  
Turbo Code ◽  
Substantial Reduction ◽  
International Standards ◽  
Extrinsic Information ◽  
Suggested Approach

This paper examines turbo codes that are currently introduced in many international standards and implemented in numerous advanced communication systems, and evaluates the process of extrinsic information transfer (EXIT). 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) charts. This approach provides a possibility to predict the bit-error rate (BER) of a turbo code system with only the extrinsic information transfer chart. It is shown that extrinsic information transfer charts are powerful tools to analyze and optimize the convergence behavior of iterative systems utilizing the turbo principle, i.e., systems exchanging and refining extrinsic information. The idea is to consider the associated soft-input soft-output (SISO) stages as information processors, which map input a priori log likelihood ratios (LLRs) onto output extrinsic LLRs, 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 extrinsic information transfer 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

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.

Sign in / Sign up

Export Citation Format

Share Document