Analysis of hard decision and soft decision decoding algorithms of LDPC codes in AWGN

2015 ◽  
Author(s):  
Rinu Jose ◽  
Ameenudeen Pe
Keyword(s):  
Ldpc Codes ◽  
Soft Decision ◽  
Decoding Algorithms ◽  
Soft Decision Decoding ◽  
Hard Decision

Loop Detection Based on Bit-Flipping Decoding Algorithm for LDPC Codes

2011 ◽  
Vol 271-273 ◽  
pp. 452-457
Author(s):  
Zhong Xun Wang ◽  
Fang Qiang Zhu ◽  
Li Liu ◽  
Juan Wang
Keyword(s):  
Additive White Gaussian Noise ◽  
Ldpc Codes ◽  
Soft Decision ◽  
Decoding Algorithm ◽  
Excellent Performance ◽  
Detection Mechanism ◽  
Decoding Algorithms ◽  
Loop Detection ◽  
Soft Decision Decoding ◽  
Parity Check Codes

In this paper, we introduce a new bit-flipping decoding algorithm for low-density parity-check codes based on loop detection mechanism, which is an extension to soft-decision decoding. This decoding algorithm's performance has been significantly improved by introducing a loop detection mechanism for the failed flipping bit and leading into the soft-decision about the reliability measure of the received symbols. Theoretical analysis shows that the complexity of this algorithm is lower. Some simulation results are given, which show that compared with other known kinds of bit-flipping decoding algorithms for LDPC codes, this new decoding on the additive white Gaussian noise channel offer excellent performance.

scholarly journals Iterative Soft-Decision Decoding of Binary Cyclic Codes

2008 ◽  
Vol 4 (2) ◽  
pp. 142 ◽  
Author(s):  
Marco Baldi ◽  
Giovanni Cancellieri ◽  
Franco Chiaraluce
Keyword(s):  
Error Correction ◽  
Cyclic Codes ◽  
Error Correcting Codes ◽  
Parity Check ◽  
Soft Decision ◽  
Coding Gain ◽  
New Approach ◽  
Decoding Algorithms ◽  
Soft Decision Decoding ◽  
Hard Decision

Binary cyclic codes achieve good error correction performance and allow the implementation of very simpleencoder and decoder circuits. Among them, BCH codesrepresent a very important class of t-error correcting codes, with known structural properties and error correction capability. Decoding of binary cyclic codes is often accomplished through hard-decision decoders, although it is recognized that softdecision decoding algorithms can produce significant coding gain with respect to hard-decision techniques. Several approaches have been proposed to implement iterative soft-decision decoding of binary cyclic codes. We study the technique based on “extended parity-check matrices”, and show that such method is not suitable for high rates or long codes. We propose a new approach, based on “reduced parity-check matrices” and “spread parity-check matrices”, that can achieve better correction performance in many practical cases, without increasing the complexity.

Improving LDPC Decoding Performance for 3D TLC NAND Flash by LLR Optimization Scheme for Hard and Soft Decision

2022 ◽  
Vol 27 (1) ◽  
pp. 1-20
Author(s):  
Lanlan Cui ◽  
Fei Wu ◽  
Xiaojian Liu ◽  
Meng Zhang ◽  
Renzhi Xiao ◽  
...  
Keyword(s):  
Error Correction ◽  
Distribution Model ◽  
Quantization Scheme ◽  
Nand Flash ◽  
Soft Decision ◽  
Ldpc Decoding ◽  
Error Correction Capability ◽  
Soft Decision Decoding ◽  
Threshold Voltage Distribution ◽  
Hard Decision

Low-density parity-check (LDPC) codes have been widely adopted in NAND flash in recent years to enhance data reliability. There are two types of decoding, hard-decision and soft-decision decoding. However, for the two types, their error correction capability degrades due to inaccurate log-likelihood ratio (LLR) . To improve the LLR accuracy of LDPC decoding, this article proposes LLR optimization schemes, which can be utilized for both hard-decision and soft-decision decoding. First, we build a threshold voltage distribution model for 3D floating gate (FG) triple level cell (TLC) NAND flash. Then, by exploiting the model, we introduce a scheme to quantize LLR during hard-decision and soft-decision decoding. And by amplifying a portion of small LLRs, which is essential in the layer min-sum decoder, more precise LLR can be obtained. For hard-decision decoding, the proposed new modes can significantly improve the decoder’s error correction capability compared with traditional solutions. Soft-decision decoding starts when hard-decision decoding fails. For this part, we study the influence of the reference voltage arrangement of LLR calculation and apply the quantization scheme. The simulation shows that the proposed approach can reduce frame error rate (FER) for several orders of magnitude.

scholarly journals A Simple Scheme for Belief Propagation Decoding of BCH and RS Codes in Multimedia Transmissions

2008 ◽  
Vol 2008 ◽  
pp. 1-12 ◽  
Author(s):  
Marco Baldi ◽  
Franco Chiaraluce
Keyword(s):  
Belief Propagation ◽  
Ldpc Codes ◽  
Block Codes ◽  
Soft Decision ◽  
Linear Block Codes ◽  
Rs Codes ◽  
Nonbinary Codes ◽  
Soft Decision Decoding ◽  
Multimedia Transmissions ◽  
A New Technique

Classic linear block codes, like Bose-Chaudhuri-Hocquenghem (BCH) and Reed-Solomon (RS) codes, are widely used in multimedia transmissions, but their soft-decision decoding still represents an open issue. Among the several approaches proposed for this purpose, an important role is played by the iterative belief propagation principle, whose application to low-density parity-check (LDPC) codes permits to approach the channel capacity. In this paper, we elaborate a new technique for decoding classic binary and nonbinary codes through the belief propagation algorithm. We focus on RS codes included in the recent CDMA2000 standard, and compare the proposed technique with the adaptive belief propagation approach, that is able to ensure very good performance but with higher complexity. Moreover, we consider the case of long BCH codes included in the DVB-S2 standard, for which we show that the usage of “pure” LDPC codes would provide better performance.

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