scholarly journals Distributed Arithmetic Coding Over Binary Erasure Channel

2021 ◽  
Author(s):  
Xianyu Wang ◽  
Cong Li ◽  
Jinlin Tan ◽  
Rui Zhang ◽  
Zhifeng Liang ◽  
...  
Keyword(s):  
Side Information ◽  
Experimental Results ◽  
Arithmetic Coding ◽  
Maximum A Posteriori ◽  
A Posteriori ◽  
Distributed Arithmetic ◽  
Residual Network ◽  
Lt Codes ◽  
Erasure Channel ◽  
Binary Erasure Channel

Abstract In this paper, the Binary Erasure Channel (BEC) is researched by Distributed Arithmetic Coding (DAC) based on Slepian-Wolf coding framework. The source and side information are modelled as a virtual BEC. The DAC decoder uses maximum a posteriori (MAP) as the criterion to recover the source. A deep residual network is used to boost the DAC decoding process. The experimental results show that our algorithm nearly achieves the same performance with LT codes under different erasure probabilities.

scholarly journals Threshold Computation for Spatially Coupled Turbo-Like Codes on the AWGN Channel

Entropy ◽  
2021 ◽  
Vol 23 (2) ◽  
pp. 240
Author(s):  
Muhammad Umar Farooq ◽  
Alexandre Graell i Amat ◽  
Michael Lentmaier
Keyword(s):  
Gaussian Noise ◽  
Belief Propagation ◽  
Additive White Gaussian Noise ◽  
Maximum A Posteriori ◽  
Prediction Methods ◽  
Threshold Analysis ◽  
A Posteriori ◽  
Awgn Channel ◽  
Efficient Prediction ◽  
Binary Erasure Channel

In this paper, we perform a belief propagation (BP) decoding threshold analysis of spatially coupled (SC) turbo-like codes (TCs) (SC-TCs) on the additive white Gaussian noise (AWGN) channel. We review Monte-Carlo density evolution (MC-DE) and efficient prediction methods, which determine the BP thresholds of SC-TCs over the AWGN channel. We demonstrate that instead of performing time-consuming MC-DE computations, the BP threshold of SC-TCs over the AWGN channel can be predicted very efficiently from their binary erasure channel (BEC) thresholds. From threshold results, we conjecture that the similarity of MC-DE and predicted thresholds is related to the threshold saturation capability as well as capacity-approaching maximum a posteriori (MAP) performance of an SC-TC ensemble.

scholarly journals Source Symbol Purging-Based Distributed Conditional Arithmetic Coding

Entropy ◽  
2021 ◽  
Vol 23 (8) ◽  
pp. 983
Author(s):  
Jingjian Li ◽  
Wei Wang ◽  
Hong Mo ◽  
Mengting Zhao ◽  
Jianhua Chen
Keyword(s):  
Posterior Probability ◽  
Side Information ◽  
Code Rate ◽  
Arithmetic Coding ◽  
Distributed Arithmetic ◽  
Context Model ◽  
Error Performance ◽  
Codeword Length ◽  
Simulation Results ◽  
Correlation Strength

A distributed arithmetic coding algorithm based on source symbol purging and using the context model is proposed to solve the asymmetric Slepian–Wolf problem. The proposed scheme is to make better use of both the correlation between adjacent symbols in the source sequence and the correlation between the corresponding symbols of the source and the side information sequences to improve the coding performance of the source. Since the encoder purges a part of symbols from the source sequence, a shorter codeword length can be obtained. Those purged symbols are still used as the context of the subsequent symbols to be encoded. An improved calculation method for the posterior probability is also proposed based on the purging feature, such that the decoder can utilize the correlation within the source sequence to improve the decoding performance. In addition, this scheme achieves better error performance at the decoder by adding a forbidden symbol in the encoding process. The simulation results show that the encoding complexity and the minimum code rate required for lossless decoding are lower than that of the traditional distributed arithmetic coding. When the internal correlation strength of the source is strong, compared with other DSC schemes, the proposed scheme exhibits a better decoding performance under the same code rate.

MAP Detection of Misbehaving Relay in Wireless Multiple Access Relay Networks

2011 ◽  
Vol 15 (3) ◽  
pp. 340-342 ◽  
Author(s):  
Sang Wu Kim ◽  
Taha Khalaf ◽  
Sangmun Kim
Keyword(s):  
False Alarm ◽  
Multiple Access ◽  
Side Information ◽  
Relay Networks ◽  
Maximum A Posteriori ◽  
A Posteriori ◽  
Probability Of False Alarm ◽  
Wireless Links ◽  
Channel Errors

We propose the maximum a posteriori (MAP) detection of the misbehaving relay that injects false data or adds channel errors into the network encoder in multiple access relay networks. The proposed scheme does not require sending extra bits at the source and is optimal in the sense of minimizing the probability of incorrect detection. We derive the probability of false alarm and misdetection, taking into account the lossy nature of wireless links. The side information regarding the presence of relay misbehavior is exploited at the decoder to mitigate the relay misbehavior and enhance the reliability of decoding.

Bayesian Inference Explains Perception of Unity and Ventriloquism Aftereffect: Identification of Common Sources of Audiovisual Stimuli

2007 ◽  
Vol 19 (12) ◽  
pp. 3335-3355 ◽  
Author(s):  
Yoshiyuki Sato ◽  
Taro Toyoizumi ◽  
Kazuyuki Aihara
Keyword(s):  
Bayesian Inference ◽  
Computational Model ◽  
Audiovisual Integration ◽  
Experimental Results ◽  
Auditory Stimuli ◽  
Maximum A Posteriori ◽  
A Posteriori ◽  
Spatial Frame ◽  
Ventriloquism Aftereffect ◽  
Audiovisual Stimuli

We study a computational model of audiovisual integration by setting a Bayesian observer that localizes visual and auditory stimuli without presuming the binding of audiovisual information. The observer adopts the maximum a posteriori approach to estimate the physically delivered position or timing of presented stimuli, simultaneously judging whether they are from the same source or not. Several experimental results on the perception of spatial unity and the ventriloquism effect can be explained comprehensively if the subjects in the experiments are regarded as Bayesian observers who try to accurately locate the stimulus. Moreover, by adaptively changing the inner representation of the Bayesian observer in terms of experience, we show that our model reproduces perceived spatial frame shifts due to the audiovisual adaptation known as the ventriloquism aftereffect.

scholarly journals Block-Based MAP Superresolution Using Feature-Driven Prior Model

2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
Feng Xu ◽  
Tanghuai Fan ◽  
Chenrong Huang ◽  
Xin Wang ◽  
Lizhong Xu
Keyword(s):  
Local Feature ◽  
Experimental Results ◽  
Maximum A Posteriori ◽  
A Posteriori ◽  
Prior Model ◽  
Expansion Strategy ◽  
Ill Posed ◽  
Block Based

In the field of image superresolution reconstruction (SRR), the prior can be employed to solve the ill-posed problem. However, the prior model is selected empirically and characterizes the entire image so that the local feature of image cannot be represented accurately. This paper proposes a feature-driven prior model relying on feature of the image and introduces a block-based maximum a posteriori (MAP) framework under which the image is split into several blocks to perform SRR. Therefore, the local feature of image can be characterized more accurately, which results in a better SRR. In process of recombining superresolution blocks, we still design a border-expansion strategy to remove a byproduct, namely, cross artifacts. Experimental results show that the proposed method is effective.

scholarly journals An Effective Error Correction Scheme for Arithmetic Coding

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Qiuzhen Lin ◽  
Kwok-Wo Wong ◽  
Ming Li ◽  
Jianyong Chen
Keyword(s):  
Error Correction ◽  
Arithmetic Coding ◽  
Maximum A Posteriori ◽  
A Posteriori ◽  
Correction Technique ◽  
Correction Scheme ◽  
Simulation Results ◽  
Forbidden Region ◽  
Better Than

We propose an effective error correction technique for arithmetic coding with forbidden symbol. By predicting the occurrence of the subsequent forbidden symbols, the forbidden region is actually expanded and theoretically, a better error correction performance can be achieved. Moreover, a generalized stack algorithm is exploited to detect the forbidden symbol beforehand. The proposed approach is combined with themaximum a posteriori(MAP) metric to keep the highly probable decoding paths in the stack. Simulation results justify that our scheme performs better than the existing MAP methods on the error correction performance, especially at a low coding rate.

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