Efficient stopping criterion for iterative decoding of turbo codes

2003 ◽  
Vol 39 (1) ◽  
pp. 73 ◽  
Author(s):  
Nam Yul Yu ◽  
Min Goo Kim ◽  
Yong Serk Kim ◽  
Sang Uoon Chung
Keyword(s):  
Turbo Codes ◽  
Iterative Decoding ◽  
Stopping Criterion

An Advanced Self-Adaptive Iterative Decoding Scheme Based on Stopping Criterion

2011 ◽  
Vol 179-180 ◽  
pp. 167-173 ◽  
Author(s):  
Shu Yang Liu ◽  
Jian Ping Li ◽  
Chao Shi Cai
Keyword(s):  
Turbo Codes ◽  
Iterative Decoding ◽  
Stopping Criterion ◽  
Lower Complexity ◽  
Simulation Results ◽  
To Receive ◽  
Self Adaptive

This paper proposes an advanced iterative decoding scheme based on stopping criterion for BICM-ID embedded turbo codes. A fixed iterative number scheme has been used in the receiver and lower complexity than the conventional schedule can be achieved. To acquire a smaller total iterative number and fewer calculations of CE, the maximum and minimum iterative numbers (Imax/Imin) are introduced in this proposed scheme. However, iterative numbers which correspond to different SNRs are varied. In order to receive better flexibility, both Imax and Imin, whose values are not unique, are determined by the statistics of the average iterative numbers and the CG criterion. Simulation results confirm that, compared with the fixed iterative number scheme, similar BER performances and much lower complexity can be achieved. Further improvement of the adaptability results from this self-adaptive option of Imax/Imin.

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.

An Improved Simplified-CE Stopping Criterion for BICM-ID System

2013 ◽  
Vol 846-847 ◽  
pp. 1262-1265
Author(s):  
Miao Miao Li ◽  
Jian Ping Li
Keyword(s):  
Iterative Decoding ◽  
Rayleigh Fading ◽  
Signal To Noise Ratio ◽  
Coded Modulation ◽  
Cross Entropy ◽  
Stopping Criterion ◽  
Transmission Scheme ◽  
Stopping Criteria ◽  
Bit Interleaved Coded Modulation ◽  
Efficient Transmission

Bit-interleaved coded modulation iterative decoding (BICM-ID) is an excellent bandwidth efficient transmission scheme,which owns remarkable bit-error-rate (BER) performance both in additive Gaussian noise (AWGN) channel and Rayleigh fading channel.But it leads to the increase of computational complexity and decoding delay at the receiver at the same time. In order to decrease the unnecessary iterations ,a variety of the stopping criteria are put forward . This paper presents an improved simplified cross-entropy (CE) stopping criterion based on Simplified-CE criterion, which calculates the value of CE just one time when Signal to Noise Ratio (SNR) is under 2dB to simplified the iterative process. Simulation results show that the improved Simplified-CE criterion can own the least iterative number when the SNR is under 2dB.And when the SNR is from 2.5dB to 4dB, it is about 12% less than CE criterion in the average iterative numbers.

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