Achieving secure transmission using feedback-based LT code with degree distribution updated

2017 ◽  
Author(s):  
Likang Wang ◽  
Jianhua Peng ◽  
Ming Yi ◽  
Kaizhi Huang ◽  
Aiqin Li
Keyword(s):  
Degree Distribution ◽  
Lt Code ◽  
Secure Transmission

scholarly journals Improving the data recovery for short length LT codes

2020 ◽  
Vol 10 (2) ◽  
pp. 1972
Author(s):  
Nadhir Ibrahim Abdulkhaleq ◽  
Faeza Abbas Abed ◽  
Ihsan Jabbar Hasan ◽  
Falah Hasan Mahdi
Keyword(s):  
Code Generation ◽  
Degree Distribution ◽  
Short Length ◽  
Data Recovery ◽  
Data Selection ◽  
Encoding Scheme ◽  
Data Packets ◽  
Lt Code ◽  
Fountain Code ◽  
Data Length

Luby Transform (LT) code is considered as an efficient erasure fountain code. The construction of the coded symbols is based on the formation of the degree distribution which played a significant role in ensuring a smooth decoding process. In this paper, we propose a new encoding scheme for LT code generation. This encoding presents a deterministic degree generation (DDG) with time hoping pattern which found to be suitable for the case of short data length where the well-known Robust Soliton Distribution (RSD) witnessed a severe performance degradation. It is shown via computer simulations that the proposed (DDG) has the lowest records for unrecovered data packets when compared to that using random degree distribution like RSD and non-uniform data selection (NUDS). The success interpreted in decreasing the overhead required for data recovery to the order of 25% for a data length of 32 packets.

A Degree Distribution Optimization Algorithm for Image Transmission

2016 ◽  
Vol 37 (3) ◽  
Author(s):  
Wei Jiang ◽  
Junjie Yang
Keyword(s):  
Optimization Algorithm ◽  
Degree Distribution ◽  
Image Transmission ◽  
Unequal Error Protection ◽  
Channel Noise ◽  
Practical Implementation ◽  
Selection Scheme ◽  
Lt Code ◽  
The Relationship

AbstractLuby Transform (LT) code is the first practical implementation of digital fountain code. The coding behavior of LT code is mainly decided by the degree distribution which determines the relationship between source data and codewords. Two degree distributions are suggested by Luby. They work well in typical situations but not optimally in case of finite encoding symbols. In this work, the degree distribution optimization algorithm is proposed to explore the potential of LT code. Firstly selection scheme of sparse degrees for LT codes is introduced. Then probability distribution is optimized according to the selected degrees. In image transmission, bit stream is sensitive to the channel noise and even a single bit error may cause the loss of synchronization between the encoder and the decoder. Therefore the proposed algorithm is designed for image transmission situation. Moreover, optimal class partition is studied for image transmission with unequal error protection. The experimental results are quite promising. Compared with LT code with robust soliton distribution, the proposed algorithm improves the final quality of recovered images obviously with the same overhead.

A Degree Distribution Optimization Algorithm in Unequal-Protected LT Code

2014 ◽  
Vol 599-601 ◽  
pp. 1313-1316
Author(s):  
Wei Jiang ◽  
Jun Jie Yang
Keyword(s):  
Optimization Algorithm ◽  
Degree Distribution ◽  
Evolutionary Strategy ◽  
Practical Implementation ◽  
Coding Systems ◽  
Source Data ◽  
Lt Code ◽  
Fountain Code ◽  
The Relationship ◽  
Unequal Loss Protection

LT code is the first practical implementation of digital fountain code. The coding behavior of LT code is mainly decided by the degree distribution which determines the relationship between source data and codeword. Since coding systems with unequal loss protection are widely applied, a degree distribution optimization algorithm is designed for unequal-protected LT code. The degree distribution that minimizes the number of un-recovered source symbols is found. By introducing the weighted cost, the optimal degree distribution can be solved by evolutionary strategy. The experimental results are quite promising. Compared with LT code with robust soliton distribution, the proposed algorithm improves the number of the recovered symbols obviously with the same overhead.

scholarly journals Design of Improved BP Decoders and Corresponding LT Code Degree Distribution for AWGN Channels

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Lei Zhang ◽  
Li Su
Keyword(s):  
Performance Improvement ◽  
Error Rate ◽  
Degree Distribution ◽  
Belief Propagation ◽  
State Of The Art ◽  
Additive White Gaussian Noise ◽  
Soft Decision ◽  
Lt Codes ◽  
Lt Code ◽  
Gaussian Noise Channels

This paper presents the performance of a hard decision belief propagation (HDBP) decoder used for Luby transform (LT) codes over additive white Gaussian noise channels; subsequently, three improved HDBP decoders are proposed. We first analyze the performance improvement of the sorted ripple and delayed decoding process in a HDBP decoder; subsequently, we propose ripple-sorted belief propagation (RSBP) as well as ripple-sorted and delayed belief propagation (RSDBP) decoders to improve the bit error rate (BER). Based on the analysis of the distribution of error encoded symbols, we propose a ripple-sorted and threshold-based belief propagation (RSTBP) decoder, which deletes low-reliability encoded symbols, to further improve the BER. Degree distribution significantly affects the performance of LT codes. Therefore, we propose a method for designing optimal degree distributions for the proposed decoders. Through simulation results, we demonstrate that the proposed RSBP and RSDBP decoders provide significantly better BER performances than the HDBP decoder. RSDBP and RSTDP combined with the proposed degree distributions outperformed state-of-the-art degree distributions in terms of the number of encoded symbols required to recover an input symbol correctly (NERRIC) and the frame error rate (FER). For a hybrid decoder formulated by combining RSDBP with a soft decision belief propagation decoder, the proposed degree distribution outperforms the other degree distributions in terms of decoding complexity.

scholarly journals Research on Degree Distribution Optimization of LT Codes

2020 ◽  
Vol 38 (3) ◽  
pp. 627-633
Author(s):  
Yachen Liu ◽  
Pengcheng Wang ◽  
Dehong Tian ◽  
Haixin Sun ◽  
Jie Qi ◽  
...  
Keyword(s):  
Acoustic Communication ◽  
Channel Coding ◽  
Degree Distribution ◽  
Orthogonal Frequency Division Multiplexing ◽  
Underwater Acoustic Communication ◽  
Underwater Acoustic ◽  
Sea Trial ◽  
Stable Performance ◽  
Lt Code ◽  
Short Code

LT code, as a channel coding scheme with good adaptability to the channel, has a stable performance in data transmission of underwater acoustic communication. In the case of large decoding overhead, the LT code can reach the ideal bit error rate(BER), but when the length of the encoded data is short, its coding and decoding performance is not ideal. LT code was applied to underwater acoustic communication by combining with orthogonal frequency division multiplexing (OFDM), and a LT-OFDM system was constructed. To improve the performance of LT code in the case of short code length, a method for degree distribution optimization was proposed on the objective of minimizing BER and minimizing average coding degree. Simulation and sea trial results show that under the same BER this method can optimize the system, transform 7%-22% conversion, and reduce the complexity of coding and decoding.

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