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The Journal of China Universities of Posts and Telecommunications 2024年第1期31卷 1-11页

作者： Yang Yujia Liu Yiming Zhang Wenjia Zhang Zhi State Key Laboratory of Networking and Switch Technology Beijing University of Posts and TelecommunicationsBeijing 100876China

With the development of deep learning(DL),joint source-channel coding(JSCC)solutions for end-to-end transmission have gained a lot of *** deep JSCC schemes support dynamically adjusting the rate according to different channel conditions during transmission,enhancing robustness in dynamic wireless ***,most of the existing adaptive JSCC schemes only consider different channel conditions,ignoring the different feature importance in the image processing and *** uniform compression of different features in the image may result in the compromise of critical image details,particularly in low signal-to-noise ratio(SNR)*** address the above issues,in this paper,a dual attention mechanism is introduced and an SNR-adaptive deep JSCC mechanism with a convolutional block attention module(CBAM)is proposed,in which matrix operations are applied to features in spatial and channel dimensions *** proposed solution concatenates the pooling feature with the SNR level and passes it sequentially through the channel attention network and spatial attention network to obtain the importance evaluation *** show that the proposed solution outperforms other baseline schemes in terms of peak SNR(PSNR)and structural similarity(SSIM),particularly in low SNR scenarios or when dealing with complex image content.

关键词： semantic communication joint source-channel coding image transmission

Topology Data Analysis-Based Error Detection for Semantic Image Transmission with Incremental Knowledge-Based HARQ

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China Communications 2025年第1期22卷 235-255页

作者： Ni Fei Li Rongpeng Zhao Zhifeng Zhang Honggang College of Information Science and Electronic Engineering Zhejiang UniversityHangzhou 310027China Zhejiang Lab Hangzhou 311121China Faculty of Data Science City University of MacaoMacaoChina

Semantic communication(SemCom)aims to achieve high-fidelity information delivery under low communication consumption by only guaranteeing semantic ***,semantic communication still suffers from unexpected channel volatility and thus developing a re-transmission mechanism(e.g.,hybrid automatic repeat request[HARQ])becomes *** that regard,instead of discarding previously transmitted information,the incremental knowledge-based HARQ(IK-HARQ)is deemed as a more effective mechanism that could sufficiently utilize the information ***,considering the possible existence of semantic ambiguity in image transmission,a simple bit-level cyclic redundancy check(CRC)might compromise the performance of ***,there emerges a strong incentive to revolutionize the CRC mechanism,thus more effectively reaping the benefits of both SemCom and *** this paper,built on top of swin transformer-based joint source-channel coding(JSCC)and IK-HARQ,we propose a semantic image transmission framework *** particular,different from the conventional CRC,we introduce a topological data analysis(TDA)-based error detection method,which capably digs out the inner topological and geometric information of images,to capture semantic information and determine the necessity for *** numerical results validate the effectiveness and efficiency of the proposed SC-TDA-HARQ framework,especially under the limited bandwidth condition,and manifest the superiority of TDA-based error detection method in image transmission.

关键词： error detection incremental knowledgebased HARQ joint source-channel coding semantic communication swin transformer topological data analysis

Video coding bit allocation algorithm over wireless transmission channel

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Journal of Harbin Institute of Technology(New Series) 2006年第5期13卷 601-606页

作者：张伟周源华 Institute of Image Communication & Information Processing Shanghai Jiaotong University Shanghai 200030 China

For two-way video communications over wireless channels using the automatic repeat request (ARQ) retransmission scheme, TMN8 rate control scheme is not effective in minimizing the number of frames skipped and cannot guarantee video quality during the retransmissions of error packets. This paper presents a joint source channel bit allocation scheme that allocates target bits according to encoder buffer fullness and estimation of channel condition by retransmission information. The results obtained from implementing our scheme in H.263+coder over wireless channel model show that our proposed scheme encodes the video sequences with lower and steadier buffer delay, fewer frames skipped and higher average PSNR compared to TMN8.

关键词： ARQ bit allocation channel model error-prone channel joint source-channel coding

joint resource allocation for MIMO-OFDM video transmission systems with unequal error protection

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Journal of Harbin Institute of Technology(New Series) 2012年第2期19卷 119-124页

作者：张成文刘鑫谭学治 Communication Research Center Harbin Institute of Technology

To improve the performance of MIMO-OFDM video transmission systems on the limitation of wireless bandwidth and transmitting power,we propose an adaptive joint resource allocation algorithm with unequal error protection(UEP) based on joint source-channel coding(JSCC) according to H.264 video compression standard and RCPT channel *** to different thresholds of the average SNR of subchannels,the algorithm dynamically allocates the source coding parameters of original video data and the channel coding parameters of RCPT,which realizes UEP for the compressed video data of different *** the bit and power allocation based on MQAM modulation and the subspace allocation based on beamforming technology for different subcarriers,an adaptive joint resource allocation making full use of space-frequency domain resources have been *** simulation results indicate that the algorithm improves the adaptability of video transmission systems in different wireless environments and the quality of video retrieval.

关键词： video transmission MIMO-OFDM unequal error protection joint source-channel coding

Task-Oriented Semantic Communication with Foundation Models

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China Communications 2024年第7期21卷 65-77页

作者： Chen Mingkai Liu Minghao Zhang Zhe Xu Zhiping Wang Lei Key Laboratory of Broadband Wireless Communication and Sensor Network Technology Ministry of EducationNanjing University of Posts and TelecommunicationsNanjing 210003China School of Ocean Information Engineering Jimei UniversityXiamen 361021China Key Laboratory of Underwater Acoustic Communication and Marine Information Technology(Xiamen University) Ministry EducationXiamen 361005China

In the future development direction of the sixth generation(6G)mobile communication,several communication models are proposed to face the growing challenges of the *** rapid development of artificial intelligence(AI)foundation models provides significant support for efficient and intelligent communication *** this paper,we propose an innovative semantic communication paradigm called task-oriented semantic communication system with foundation ***,we segment the image by using task prompts based on the segment anything model(SAM)and contrastive language-image pretraining(CLIP).Meanwhile,we adopt Bezier curve to enhance the mask to improve the segmentation ***,we have differentiated semantic compression and transmission approaches for segmented ***,we fuse different semantic information based on the conditional diffusion model to generate high-quality images that satisfy the users'specific task ***,the experimental results show that the proposed system compresses the semantic information effectively and improves the robustness of semantic communication.

关键词： diffusion model foundation model joint source-channel coding task-oriented semantic communication

Robust transmission of progressive image bitstreams based on DCT over broadband wireless channels

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Journal of Harbin Institute of Technology(New Series) 2006年第2期13卷 219-225页

作者：王东华周源华马曾栋 Institute of Image Communication & Information Processing Shanghai Jiaotong University Shanghai 200030 China Research Institute of Communication Technology Harbin Institute of Technology Harbin 150001 China

A robust progressive image transmission scheme over broadband wireless fading channels is developed for 4th generation wireless communication systems （4G） in this paper. The proposed scheme is based on space-time block coded orthogonal frequency-division multiplexing （OFDM） with 4 transmit antennas and 2 receive antennas and uses a simplified minimum mean square error （MMSE） detector instead of maximum likelihood （ML） detectors. Considering DCT is simpler and more widely applied in the industry than wavelet transforms, a progressive image compression method based on DCT called mean-subtract embedded DCT （MSEDCT） is developed, with a simple mean-subtract method for the redundancy of reorganized DC blocks in addition to a structure similar to the embedded zerotree wavelet coding （EZW） method. Then after analyzing and testing bit importance of the progressive MSEDCT bitstreams, the layered unequal error protection method of joint source-channels coding based on Reed-Solomon （RS） codes is used to protect different parts of bitstreams, providing different QoS assurances and good flexibility. Simulation experiments show our proposed scheme can effectively degrade fading effects and obtain better image transmission effects with 10 -20 dB average peak-sig- nal-noise-ratio （PSNR） gains at the median Eb/No than those schemes without space-time coded OFDM or equal error protections with space-time coded OFDM.

关键词： broadband communication embedded source coding image transmission joint source-channel coding

joint source-channel Bit Allocation Based on Expected End-to-End Distortion Model

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Journal of Donghua University(English Edition) 2010年第4期27卷 458-462页

作者：马汉杰陈耀武 Institute of Advanced Digital Technology and Instrumentation Zhejiang University

An adaptive joint source channel bit allocation method for video communications over error-prone channel is *** protect the bit-streams from the channel bit errors,the rate compatible punctured convolution(RCPC)code is used to produce coding rates varying from 4/5 to 1/2 using the same encoder and the Viterbi *** expected end-to-end distortion model was presented to estimate the distortion introduced in compressed source coding due to quantization and channel bit errors *** on the proposed end-to-end distortion model,an adaptive joint source-channel bit allocation method was proposed under time-varying error-prone channel *** results show that the proposed methods could utilize the available channel capacity more efficiently and achieve better video quality than the other fixed coding-based bit allocation methods when transmitting over error-prone channels.

关键词： joint source-channel coding end-to-end distortion bit allocation rate compatible punctured convolution code