An Improved Construction for Yielding Nonbinary LDPC Codes

2014 ◽  
Vol 556-562 ◽  
pp. 6307-6310
Author(s):  
Li Sheng Zhang ◽  
Zhi Peng Huang ◽  
Fan Xin Zeng
Keyword(s):  
Belief Propagation ◽  
Ldpc Codes ◽  
Construction Method ◽  
Decoding Algorithm ◽  
Construction Methods ◽  
Awgn Channel ◽  
Simulation Results ◽  
Nonbinary Ldpc Codes

In this paper, we investigate construction methods for producing nonbinary LDPC codes, and a family of nonbinary LDPC codes over is presented and its properties are derived. Compared to the second method presented by Ref. [5], simulation results show that the proposed LDPC codes perform well over the AWGN channel under belief propagation decoding algorithm and have an almost same BER curve as the ones in Ref. [5]. However, the resultant construction method is simpler than the latter’s.

scholarly journals Node-Subset Scheduling with a Subset-Reset Mechanism for the Decoding Algorithm of Nonbinary LDPC Codes

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Wentao Fu ◽  
Xilun Luo ◽  
Yuanfa Ji ◽  
Xiyan Sun
Keyword(s):  
Ldpc Codes ◽  
Sliding Window ◽  
Low Complexity ◽  
Performance Degradation ◽  
Decoding Algorithm ◽  
Processing Node ◽  
Simulation Results ◽  
Nonbinary Ldpc Codes

For the conventional extended min-sum (EMS) algorithm, all check nodes update their check-to-variable (C2V) messages in every iteration. Selected scheduling, which reduces the number of check nodes for message updating in one iteration, can effectively reduce the complexity of the decoding algorithm, but it also lead to some performance degradation. With the introduction of a metric based on node stability, we propose stability-based node-subset scheduling (SNS) for the EMS algorithm, which can improve the performance of node-subset scheduling (NS). Second, to further improve the decoding performance of SNS while maintaining low complexity, we propose the SNS-EMS algorithm with a subset-reset mechanism (RSNS-EMS) based on the abnormal stability found in the processing node subset, which will cause the estimated codeword to fail to converge. The RSNS-EMS algorithm enhances performance through a sliding window detection and reset mechanism, and it resets the elements in the processing node subset to force all check nodes to update new messages when abnormal stability is detected. The simulation results show that the proposed algorithm can reduce complexity by approximately 25% with negligible performance degradation.

A BP Decoding Algorithm Based on Nodes Residual for LDPC Codes and its Hardware Implementation

2011 ◽  
Vol 128-129 ◽  
pp. 7-10
Author(s):  
Zhong Xun Wang ◽  
Xing Cheng Wang ◽  
Fang Qiang Zhu
Keyword(s):  
Hardware Implementation ◽  
Belief Propagation ◽  
Dynamic Scheduling ◽  
Ldpc Codes ◽  
Ldpc Code ◽  
Low Complexity ◽  
Decoding Algorithm ◽  
Fast Decoding ◽  
Good For

We researched BP decoding algorithm based on variable-to-check information residual for LDPC code (VC-RBP) in this paper. It is a dynamic scheduling belief propagation using residuals, and has some advantages，such as fast decoding, good performance, and low complexity. It is similar to residual belief propagation (RBP),but has some difference in computing the residual message. This paper further optimized the new algorithm on DSP of TMS320dm6446, and it is good for hardware implementation.

scholarly journals A Doping Bits Based BP Decoding for Rateless Distributed Source Coding Applications

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
N. M. Masoodhu Banu ◽  
S. Sasikumar
Keyword(s):  
Belief Propagation ◽  
Source Coding ◽  
Ldpc Codes ◽  
Distributed Source Coding ◽  
Decoding Algorithm ◽  
Likelihood Ratios ◽  
Regular Source ◽  
Log Likelihood ◽  
Rate Adaptive ◽  
Decoder Complexity

A novel doping bits based belief propagation decoding algorithm, for rate-adaptive LDPC codes based on fixed bipartite graph code, is proposed. The proposed work modifies the decoding algorithm, by converting the puncturing nodes to regular source nodes and by following the encoding rule at the decoder. The transmitted doping bits in place of punctured bits, with the modified decoding algorithm at the decoder, feed all the punctured nodes with reliable log likelihood ratios. This enables the proposed decoding algorithm to recover all punctured nodes in the early iteration. The fast convergence leads to decoder complexity reduction while providing considerable improvement in performance.

Modified Iterative Sphere Decoding Algorithm in LTE System

2013 ◽  
Vol 765-767 ◽  
pp. 611-614
Author(s):  
Qin Zhu ◽  
Xiao Wen Li
Keyword(s):  
Channel Equalization ◽  
Detection Algorithm ◽  
Qr Decomposition ◽  
Sphere Decoding ◽  
Decoding Algorithm ◽  
Algorithm Performance ◽  
Awgn Channel ◽  
Term Evolution ◽  
Simulation Results

In the long-term evolution (LTE) system, channel equalization makes compensation to restore the original signal, the paper puts forward iteration sphere decoding algorithm which combines traditional sphere decoding and the improved QR based on the conventional QR decomposition detection algorithm. It can effectively reduce the system complexity. At the same time, in QPSK and 16QAM, the simulation results show that the improved QR iterative sphere decoding algorithm performance is better with higher SNR in AWGN channel.

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