Code rate and the area under extrinsic information transfer curves

2003 ◽  
Author(s):  
A. Ashikhmin ◽  
G. Kramer ◽  
S. ten Brink
Keyword(s):  
Information Transfer ◽  
Code Rate ◽  
Extrinsic Information

scholarly journals On efficient designing of protograph LDPC codes

2021 ◽  
Vol 19 (6.2) ◽  
pp. 39
Author(s):  
Huong-Giang Nguyen ◽  
Nghia Xuan Pham ◽  
Thu Phuong Nguyen ◽  
Chi Dinh Nguyen
Keyword(s):  
Information Transfer ◽  
Ldpc Codes ◽  
Code Rate ◽  
Weight Enumerator ◽  
Error Floor ◽  
Extrinsic Information ◽  
Simple Method ◽  
Prior Art ◽  
Simulation Results

This paper designs two protograph LDPC codes with code-rate $R > 1/2$. A simple method using the protograph extrinsic information transfer (PEXIT) to design the codes with a low decoding threshold and the asymptotic weight enumerator (AWE) to evaluate the error floor of the codes is deployed. Simulation results show that the proposed codes have a better error floor than prior art protograph codes and offer higher rate protographs.

scholarly journals Optimized Design for NB-LDPC-Coded High-Order CPM: Power and Iterative Efficiencies

Symmetry ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1353
Author(s):  
Rui Xue ◽  
Tong Wang ◽  
Yanbo Sun ◽  
Huaiyu Tang
Keyword(s):  
Spectral Efficiency ◽  
Power Efficiency ◽  
Information Transfer ◽  
Continuous Phase ◽  
Code Rate ◽  
High Order ◽  
Continuous Phase Modulation ◽  
Optimized Design ◽  
Extrinsic Information ◽  
Step Method

In this paper, a non-binary low-density parity-check (NB-LDPC) coded high-order continuous phase modulation (CPM) system is designed and optimized to improve power and iterative efficiencies. Firstly, the minimum squared normalized Euclidean distance and the 99% double-sided power bandwidth are introduced to design a competitive CPM, improving its power efficiency under a given code rate and spectral efficiency. Secondly, a three-step method based on extrinsic information transfer (EXIT) and entropy theory is used to design NB-LDPC codes, which reduces the convergence threshold approximately 0.42 and 0.58 dB compared with the candidate schemes. Thirdly, an extrinsic information operation is proposed to address the positive feedback issue in iterative detection and decoding and the value of bit error rate (BER) can approximately be reduced by 5×10−3. Finally, iteration optimization employing the EXIT chart and mutual information between demodulation and decoding is performed to achieve a suitable tradeoff for the communication reliability and iterative decoding delay. Simulation results show that the resulting scheme provides an approximately 3.95 dB coding gain compared to the uncoded CPM and achieves approximately 0.5 and 0.7 dB advantages compared with the candidate schemes. The resulting NB-LDPC-coded high-order CPM for a given code rate and spectral efficiency converges earlier into a turbo cliff region compared with other competitors and significantly improves power and iterative efficiencies.

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.

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