We improve the iterative decoding algorithm by utilizing the “leaked” residual redundancy at the output of the source encoder without changing the encoder structure for the noisy channel. The experimental results sh...We improve the iterative decoding algorithm by utilizing the “leaked” residual redundancy at the output of the source encoder without changing the encoder structure for the noisy channel. The experimental results show that using the residual redundancy of the compressed source in channel decoding is an effective method to improve the error correction performance.展开更多
Most of multimedia schemes employ variable-length codes (VLCs) like Huffman code as core components in obtaining high compression rates. However VLC methods are very sensitive to channel noise. The goal of this pape...Most of multimedia schemes employ variable-length codes (VLCs) like Huffman code as core components in obtaining high compression rates. However VLC methods are very sensitive to channel noise. The goal of this paper is to salvage as many data from the damaged packets as possible for higher audiovisual quality. This paper proposes an integrated joint source-channel decoder (I-JSCD) at a symbol-level using three-dimensional (3-D) trellis representation for first-order Markov sources encoded with VLC source code and convolutional channel code. This method combines source code and channel code state-spaces and bit-lengths to construct a two-dimensional (2-D) state-space, and then develops a 3-D trellis and a maximum a-posterior (MAP) algorithm to estimate the source sequence symbol by symbol. Experiment results demonstrate that our method results in significant improvement in decoding performance, it can salvage at least half of (50%) data in any channel error rate, and can provide additional error resilience to VLC stream like image, audio, video stream over high error rate links.展开更多
This paper proposes an integrated joint source-channel decoder (I-JSCD) using Max-Log-MAP method for sources encoded with exp-Golomb codes and convolutional codes, and proposes a system applying this method to decod...This paper proposes an integrated joint source-channel decoder (I-JSCD) using Max-Log-MAP method for sources encoded with exp-Golomb codes and convolutional codes, and proposes a system applying this method to decoding the VLC data, e.g. motion vector differences (MVDs), of H.264 across an AWGN channel. This method combines the source code state-space and the channel code state-space together to construct a joint state-space, develops a 3-D trellis and a maximum a-posterior (MAP) algorithm to estimate the source sequence symbol by symbol, and then uses max-log approximation to simplify the algorithm. Experiments indicate that the proposed system gives significant improvements on peak signal-to-noise ratio (PSNR) (maximum about 15 dB) than a separate scheme. This also leads to a higher visual quality of video stream over a highly noisy channel.展开更多
A new arithmetic coding system combining source channel coding and maximum a posteriori decoding were proposed. It combines source coding and error correction tasks into one unified process by introducing an adaptive ...A new arithmetic coding system combining source channel coding and maximum a posteriori decoding were proposed. It combines source coding and error correction tasks into one unified process by introducing an adaptive forbidden symbol. The proposed system achieves fixed length code words by adaptively adjusting the probability of the forbidden symbol and adding tail digits of variable length. The corresponding improved MAP decoding metric was derived. The proposed system can improve the performance. Simulations were performed on AWGN channels with various noise levels by using both hard and soft decision with BPSK modulation.The results show its performance is slightly better than that of our adaptive arithmetic error correcting coding system using a forbidden symbol.展开更多
A novel Joint Source and Channel Decoding (JSCD) scheme for Variable Length Codes (VLCs) concatenated with turbo codes utilizing a new super-trellis decoding algorithm is presented in this letter. The basic idea of ou...A novel Joint Source and Channel Decoding (JSCD) scheme for Variable Length Codes (VLCs) concatenated with turbo codes utilizing a new super-trellis decoding algorithm is presented in this letter. The basic idea of our decoding algorithm is that source a priori information with the form of bit transition probabilities corresponding to the VLC tree can be derived directly from sub-state transitions in new composite-state represented super-trellis. A Maximum Likelihood (ML) decoding algorithm for VLC sequence estimations based on the proposed super-trellis is also described. Simu-lation results show that the new iterative decoding scheme can obtain obvious encoding gain especially for Reversible Variable Length Codes (RVLCs),when compared with the classical separated turbo decoding and the previous joint decoding not considering source statistical characteristics.展开更多
无线图像传输面临着带宽和计算资源的双重挑战,在节点计算能力有限的物联网等应用场景中尤为突出.联合信源信道编码(Joint Source-Channel Coding,JSCC)能够同时优化信源和信道编码,逐渐成为无线图像传输中一个重要研究方向.近年来,基...无线图像传输面临着带宽和计算资源的双重挑战,在节点计算能力有限的物联网等应用场景中尤为突出.联合信源信道编码(Joint Source-Channel Coding,JSCC)能够同时优化信源和信道编码,逐渐成为无线图像传输中一个重要研究方向.近年来,基于深度学习的JSCC方法受到广泛关注,其通过端到端训练实现编码器与解码器的联合优化.然而,大多数基于深度学习的JSCC方法的编码器涉及大量的线性与非线性运算,导致计算复杂度较高,难以应用于物联网边缘计算节点等计算资源受限的设备.为实现轻量化的编码过程,本文提出了一种基于深度压缩感知的联合信源信道编码方法BCS-JSCC(Block Compressive Sensing-Joint Source Channel Coding),实现对于编解码器的端到端优化.该方法在编码端设计可学习尺度二值化测量的压缩感知采样,实现噪声环境下匹配解码器的轻量化编码方法;在解码端,基于MMSE(Minimum Mean Squared Error)准则求解测量值传输的线性逆问题,获得信道噪声敏感的初始重建,抑制噪声对参数复用重建网络的影响.与现有的基于深度学习的JSCC方法相比,在保持编码端每像素浮点计算次数(FLOating Point operations per pixel,FLOPs per pixel)相同的条件下,本文所提出的BCS-JSCC方法在高信噪比条件下可以取得更好的传输性能.在低算力(0.10 K FLOPs/pixel)情况下,优势更为明显.本文提出的BCS-JSCC方法编码器构造简单、计算量低,适用于物联网边缘计算节点等低算力设备部署.展开更多
该文利用GSM EFR(Enhanced Full Rate)语音编码参数的冗余信息,提出了一种新的基于迭代结构和参数估计的联合解码算法框架;针对GSM EFR编码参数由非等概分布和帧间相关性提供的冗余量,本文提出了联合解码算法中两类冗余信息在信道解码,...该文利用GSM EFR(Enhanced Full Rate)语音编码参数的冗余信息,提出了一种新的基于迭代结构和参数估计的联合解码算法框架;针对GSM EFR编码参数由非等概分布和帧间相关性提供的冗余量,本文提出了联合解码算法中两类冗余信息在信道解码,信源解码的分配方案。同时针对不同语音编码参数的特性,引入不同的估计准则。仿真结果表明,该文算法显著提高了GSM EFR参数接收性能,提高了解码语音信噪比,改善了接收系统性能。展开更多
摘要We improve the iterative decoding algorithm by utilizing the “leaked” residual redundancy at the output of the source encoder without changing the encoder structure for the noisy channel. The experimental results show that using the residual redundancy of the compressed source in channel decoding is an effective method to improve the error correction performance.
基金Supported by the Foundation of Ministry of Education of China (211CERS10)
摘要Most of multimedia schemes employ variable-length codes (VLCs) like Huffman code as core components in obtaining high compression rates. However VLC methods are very sensitive to channel noise. The goal of this paper is to salvage as many data from the damaged packets as possible for higher audiovisual quality. This paper proposes an integrated joint source-channel decoder (I-JSCD) at a symbol-level using three-dimensional (3-D) trellis representation for first-order Markov sources encoded with VLC source code and convolutional channel code. This method combines source code and channel code state-spaces and bit-lengths to construct a two-dimensional (2-D) state-space, and then develops a 3-D trellis and a maximum a-posterior (MAP) algorithm to estimate the source sequence symbol by symbol. Experiment results demonstrate that our method results in significant improvement in decoding performance, it can salvage at least half of (50%) data in any channel error rate, and can provide additional error resilience to VLC stream like image, audio, video stream over high error rate links.
基金Supported by the Foundation of Ministry of Education of China (211CERS10)
摘要This paper proposes an integrated joint source-channel decoder (I-JSCD) using Max-Log-MAP method for sources encoded with exp-Golomb codes and convolutional codes, and proposes a system applying this method to decoding the VLC data, e.g. motion vector differences (MVDs), of H.264 across an AWGN channel. This method combines the source code state-space and the channel code state-space together to construct a joint state-space, develops a 3-D trellis and a maximum a-posterior (MAP) algorithm to estimate the source sequence symbol by symbol, and then uses max-log approximation to simplify the algorithm. Experiments indicate that the proposed system gives significant improvements on peak signal-to-noise ratio (PSNR) (maximum about 15 dB) than a separate scheme. This also leads to a higher visual quality of video stream over a highly noisy channel.
基金The National Natural Science Foundation ofChina(No60332030)
摘要A new arithmetic coding system combining source channel coding and maximum a posteriori decoding were proposed. It combines source coding and error correction tasks into one unified process by introducing an adaptive forbidden symbol. The proposed system achieves fixed length code words by adaptively adjusting the probability of the forbidden symbol and adding tail digits of variable length. The corresponding improved MAP decoding metric was derived. The proposed system can improve the performance. Simulations were performed on AWGN channels with various noise levels by using both hard and soft decision with BPSK modulation.The results show its performance is slightly better than that of our adaptive arithmetic error correcting coding system using a forbidden symbol.
基金Supported by the National Natural Science Foundation of China (No.90304003, No.60573112, No.60272056)the Foundation Project of China (No.A1320061262).
摘要A novel Joint Source and Channel Decoding (JSCD) scheme for Variable Length Codes (VLCs) concatenated with turbo codes utilizing a new super-trellis decoding algorithm is presented in this letter. The basic idea of our decoding algorithm is that source a priori information with the form of bit transition probabilities corresponding to the VLC tree can be derived directly from sub-state transitions in new composite-state represented super-trellis. A Maximum Likelihood (ML) decoding algorithm for VLC sequence estimations based on the proposed super-trellis is also described. Simu-lation results show that the new iterative decoding scheme can obtain obvious encoding gain especially for Reversible Variable Length Codes (RVLCs),when compared with the classical separated turbo decoding and the previous joint decoding not considering source statistical characteristics.
摘要无线图像传输面临着带宽和计算资源的双重挑战,在节点计算能力有限的物联网等应用场景中尤为突出.联合信源信道编码(Joint Source-Channel Coding,JSCC)能够同时优化信源和信道编码,逐渐成为无线图像传输中一个重要研究方向.近年来,基于深度学习的JSCC方法受到广泛关注,其通过端到端训练实现编码器与解码器的联合优化.然而,大多数基于深度学习的JSCC方法的编码器涉及大量的线性与非线性运算,导致计算复杂度较高,难以应用于物联网边缘计算节点等计算资源受限的设备.为实现轻量化的编码过程,本文提出了一种基于深度压缩感知的联合信源信道编码方法BCS-JSCC(Block Compressive Sensing-Joint Source Channel Coding),实现对于编解码器的端到端优化.该方法在编码端设计可学习尺度二值化测量的压缩感知采样,实现噪声环境下匹配解码器的轻量化编码方法;在解码端,基于MMSE(Minimum Mean Squared Error)准则求解测量值传输的线性逆问题,获得信道噪声敏感的初始重建,抑制噪声对参数复用重建网络的影响.与现有的基于深度学习的JSCC方法相比,在保持编码端每像素浮点计算次数(FLOating Point operations per pixel,FLOPs per pixel)相同的条件下,本文所提出的BCS-JSCC方法在高信噪比条件下可以取得更好的传输性能.在低算力(0.10 K FLOPs/pixel)情况下,优势更为明显.本文提出的BCS-JSCC方法编码器构造简单、计算量低,适用于物联网边缘计算节点等低算力设备部署.