Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

IEEE Communications Letters

A Systolic LLR Generation Architecture for Non-Binary LDPC Decoders

Ali Chamas Al Ghouwayel, Emmanuel Boutillon

Published Jul 6, 2011• 17 citations
Publisher

Abstract

Non-Binary LDPC codes offer higher performances than their binary counterpart but suffer from higher decoding complexity. A solution to reduce the decoding complexity is to use the Extended Min-Sum algorithm. The first step of this algorithm requires the generation of the first n_m largest Log-Likelihood Ratio (LLR), sorted in increasing order, of each received symbol. In the case where GF(q) symbols are transmitted using a BPSK modulation, we propose a simple systolic architecture that generates the sorted list of symbols.

DOI
10.1109/lcomm.2011.061611.110268

Related papers

Reduced-complexity extended Min-sum check node processing for non-binary LDPC decoding

Xinmiao Zhang, Fang Cai

Non-binary low-density parity-check (NB-LDPC) codes can achieve higher coding gain than binary LDPC codes when the code length is moderate at the cost of higher complexity. One major step of NB-LDPC decoding is check node processing. Previously, iterative forward-backward approaches are employed to implement this step. However, the storage of the intermediate results of the forward and backward computations requires large memory. In this paper, a novel check node processing scheme and corresponding VLSI architectures are proposed for the extended Min-sum NB-LDPC decoding. The proposed scheme only stores a limited number of sorted variable-to-check messages. Then the check-to-variable messages for different variable node are generated independently. For a (837, 726) NB-LDPC code over GF(25), the proposed architecture only requires 64% of the area of the previous design with the same throughput and error-correcting performance.

IEEE International Midwest Symposium on Circuits and Systems (MWSCAS)•Aug 1, 2010•5 citations

Reduced-Complexity Decoding of LDPC Codes

Reduced-Complexity Decoding of LDPC Codes Various log-likelihood-ratio-based belief-propagation (LLR- BP) decoding algorithms and their reduced-complexity derivatives for low-density parity-check (LDPC) codes are presented. Numerically accurate representations of the check-node update computation used in LLR-BP decoding are described. Furthermore, approximate representation of the decoding computations are shown to achieve a reduction in complexity, by simplifying the check-node update or symbol-node update, or both. In particular, two main approaches for simplified check-node updates are presented that are based on the so-called min-sum approximation coupled with either a normalization term or an additive offset term. Density evolution is used to analyze the performance of these decoding algorithms, to determine the optimum values of the key parameters, and to evaluate finite quantization effects. Simulation results show that these reduced-complexity decoding algorithms for LDPC codes achieve a performance very close to that of the BP algorithm. The unified treatment of decoding techniques for LDPC codes presented here provides flexibility in selecting the appropriate scheme from a performance, latency, computational complexity, and memory-requirement perspective.

IEEE Transactions on Communications•Jul 1, 2005•27 citations

Improved LDPC decoding algorithms based on min-sum algorithm

Y.V. A. C. Kumara, Chandika Bandara Wavegedara

Low-Density Parity check (LDPC) codes offer high-performance error correction near the Shannon limit which employs large code lengths and some iterations in the decoding process. The conventional decoding algorithm of LDPC is the Log Likelihood Ratio based Belief Propagation (LLR BP) which is also known as the `Sum-Product algorithm' which gives the best decoding performance and requires the most computational complexity and implementations with increased hardware complexity. Another simpler variant of this algorithm is used which is known as `min-sum algorithm' which reduces computational complexity as well as hardware complexity but with reduced accuracy. This paper analyzes the reason min-sum algorithm is more prone to errors when compared to the sum-product algorithm, and puts forward two improved algorithms which improve the performance of the min-sum algorithm with comparable algorithmic complexity.

Moratuwa Engineering Research Conference (MERCon)•Apr 1, 2016•8 citations

LOW COMPLEXITY DESIGN OF NON-BINARY LDPC DECODER USING EXTENDED MIN-SUM ALGORITHM

C.S.Elamaran

Low Density Parity Check (LDPC) codes, is a linear block code having the decoding performance closer to Shannon's limit.Nonbinary LDPC is the class of binary LDPC, which works on the higher order Galois field.The decoding performance of non-binary (NB) LDPC is better than binary LDPC for moderate code lengths.The increased computation with the increased order of field is the major challenge in hardware realization of NB-LDPC.The extension of conventional sum-product algorithm, known as extended Min-Sum (EMS) algorithm, with reduced computational complexity is used in this paper.However, a tradeoff exists between computational complexity and decoding performance. This paper aims at reducing the computational complexity by focusing on the Parity Check Matrix (PCM) modifications. The bottleneck of the design is large memory requirement and more computation intensive. The modification in the EMS algorithm can be incorporated to design low complexity hardware architecture of NB-LDPC decoder.

International Journal of Research in Engineering and Technology•Apr 25, 2015•1 citation

Low-complexity probability generation algorithm for stochastic decoding of non-binary LDPC codes

Guanghua He, Baoming Bai

Non-binary LDPC codes offer higher performances than their binary counterpart but suffer from highest decoding complexity. A solution to reduce the decoding complexity is the use of stochastic decoding algorithm, but the computational complexity of probability generation in the first step is very high. In this paper, we propose a simple method to fast generate the probability especially in high-order modulation schemes. Simulation results show that the proposed algorithm causes negligible performance degradation with reduction in computational complexity for stochastic decoding of non-binary LDPC codes, which gives some advantages in hardware implementation of the decoders.

International ICST Conference on Communications and Networking in China•Aug 1, 2011•0 citations

Reduced-Complexity Decoding of LDPC Codes

J. Chen, Ajay Dholakia, Evangelos S. Eleftheriou +2 more

Various log-likelihood-ratio-based belief-propagation (LLR-BP) decoding algorithms and their reduced-complexity derivatives for low-density parity-check (LDPC) codes are presented. Numerically accurate representations of the check-node update computation used in LLR-BP decoding are described. Furthermore, approximate representations of the decoding computations are shown to achieve a reduction in complexity by simplifying the check-node update, or symbol-node update, or both. In particular, two main approaches for simplified check-node updates are presented that are based on the so-called min-sum approximation coupled with either a normalization term or an additive offset term. Density evolution is used to analyze the performance of these decoding algorithms, to determine the optimum values of the key parameters, and to evaluate finite quantization effects. Simulation results show that these reduced-complexity decoding algorithms for LDPC codes achieve a performance very close to that of the BP algorithm. The unified treatment of decoding techniques for LDPC codes presented here provides flexibility in selecting the appropriate scheme from performance, latency, computational-complexity, and memory-requirement perspectives.

IEEE Transactions on Communications•Aug 1, 2005•952 citations
Non-Binary LDPC codes offer higher performances than their binary counterpart but suffer from higher decoding complexity. A solution to reduce the decoding complexity is to use the Extended Min-Sum algorithm. The first step of this algorithm requires the generation of the first n_m largest Log-Likelihood Ratio (LLR), sorted in increasing order, of each received symbol. In the case where GF(q) symbols are transmitted using a BPSK modulation, we propose a simple systolic architecture that generates the sorted list of symbols.
Non-binary low-density parity-check (NB-LDPC) codes can achieve higher coding gain than binary LDPC codes when the code length is moderate at the cost of higher complexity. One major step of NB-LDPC decoding is check node processing. Previously, iterative forward-backward approaches are employed to implement this step. However, the storage of the intermediate results of the forward and backward computations requires large memory. In this paper, a novel check node processing scheme and corresponding VLSI architectures are proposed for the extended Min-sum NB-LDPC decoding. The proposed scheme only stores a limited number of sorted variable-to-check messages. Then the check-to-variable messages for different variable node are generated independently. For a (837, 726) NB-LDPC code over GF(25), the proposed architecture only requires 64% of the area of the previous design with the same throughput and error-correcting performance.
Reduced-Complexity Decoding of LDPC Codes Various log-likelihood-ratio-based belief-propagation (LLR- BP) decoding algorithms and their reduced-complexity derivatives for low-density parity-check (LDPC) codes are presented. Numerically accurate representations of the check-node update computation used in LLR-BP decoding are described. Furthermore, approximate representation of the decoding computations are shown to achieve a reduction in complexity, by simplifying the check-node update or symbol-node update, or both. In particular, two main approaches for simplified check-node updates are presented that are based on the so-called min-sum approximation coupled with either a normalization term or an additive offset term. Density evolution is used to analyze the performance of these decoding algorithms, to determine the optimum values of the key parameters, and to evaluate finite quantization effects. Simulation results show that these reduced-complexity decoding algorithms for LDPC codes achieve a performance very close to that of the BP algorithm. The unified treatment of decoding techniques for LDPC codes presented here provides flexibility in selecting the appropriate scheme from a performance, latency, computational complexity, and memory-requirement perspective.
Low-Density Parity check (LDPC) codes offer high-performance error correction near the Shannon limit which employs large code lengths and some iterations in the decoding process. The conventional decoding algorithm of LDPC is the Log Likelihood Ratio based Belief Propagation (LLR BP) which is also known as the `Sum-Product algorithm' which gives the best decoding performance and requires the most computational complexity and implementations with increased hardware complexity. Another simpler variant of this algorithm is used which is known as `min-sum algorithm' which reduces computational complexity as well as hardware complexity but with reduced accuracy. This paper analyzes the reason min-sum algorithm is more prone to errors when compared to the sum-product algorithm, and puts forward two improved algorithms which improve the performance of the min-sum algorithm with comparable algorithmic complexity.
Low Density Parity Check (LDPC) codes, is a linear block code having the decoding performance closer to Shannon's limit.Nonbinary LDPC is the class of binary LDPC, which works on the higher order Galois field.The decoding performance of non-binary (NB) LDPC is better than binary LDPC for moderate code lengths.The increased computation with the increased order of field is the major challenge in hardware realization of NB-LDPC.The extension of conventional sum-product algorithm, known as extended Min-Sum (EMS) algorithm, with reduced computational complexity is used in this paper.However, a tradeoff exists between computational complexity and decoding performance. This paper aims at reducing the computational complexity by focusing on the Parity Check Matrix (PCM) modifications. The bottleneck of the design is large memory requirement and more computation intensive. The modification in the EMS algorithm can be incorporated to design low complexity hardware architecture of NB-LDPC decoder.
Non-binary LDPC codes offer higher performances than their binary counterpart but suffer from highest decoding complexity. A solution to reduce the decoding complexity is the use of stochastic decoding algorithm, but the computational complexity of probability generation in the first step is very high. In this paper, we propose a simple method to fast generate the probability especially in high-order modulation schemes. Simulation results show that the proposed algorithm causes negligible performance degradation with reduction in computational complexity for stochastic decoding of non-binary LDPC codes, which gives some advantages in hardware implementation of the decoders.
Various log-likelihood-ratio-based belief-propagation (LLR-BP) decoding algorithms and their reduced-complexity derivatives for low-density parity-check (LDPC) codes are presented. Numerically accurate representations of the check-node update computation used in LLR-BP decoding are described. Furthermore, approximate representations of the decoding computations are shown to achieve a reduction in complexity by simplifying the check-node update, or symbol-node update, or both. In particular, two main approaches for simplified check-node updates are presented that are based on the so-called min-sum approximation coupled with either a normalization term or an additive offset term. Density evolution is used to analyze the performance of these decoding algorithms, to determine the optimum values of the key parameters, and to evaluate finite quantization effects. Simulation results show that these reduced-complexity decoding algorithms for LDPC codes achieve a performance very close to that of the BP algorithm. The unified treatment of decoding techniques for LDPC codes presented here provides flexibility in selecting the appropriate scheme from performance, latency, computational-complexity, and memory-requirement perspectives.