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GCRA-FWVAE:Anomaly detection for IIoT univariate time series using time-frequency domain analysis 认领 引用 被引量：1
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作者 Xiaoling Tao Haowei Liu +3 位作者 Wenbo Zhao Weikun Li Yaqi Nie Jingqi Fu 《Digital Communications and Networks》 SCIE EI CSCD 2026年第3期405-416,共12页
With the rapid development of Artificial Intelligence of Things(AIoT)technologies,the security of Industrial Internet of Things(IIoT)data faces increasing challenges,particularly in time series anomaly detection.IIoT ... With the rapid development of Artificial Intelligence of Things(AIoT)technologies,the security of Industrial Internet of Things(IIoT)data faces increasing challenges,particularly in time series anomaly detection.IIoT data are typically scarce in abnormal samples and noisy,making unsupervised learning a common solution.The security challenges of IIoT data in AIoT environments require robust unsupervised anomaly detection methods.While Variational Autoencoders(VAEs)excel in noise resilience,they face two critical challenges in IIoT data:difficulties in single-variable time-series modeling and conflicts between static prior assumptions and dynamic temporal features.To address these challenges,we propose the Greater Cane Rat Algorithm-enhanced FourierWavelet Conditional Variational Autoencoder(GCRA-FWVAE).Our method introduces a time-frequency dualbranch architecture that synergistically combines wavelet transforms for localized transient feature extraction and Fourier transforms for global spectral characterization.These complementary representations jointly regulate the Conditional Variational Autoencoder(CVAE)reconstruction process,effectively preserving critical anomaly signatures while suppressing noise interference.The architecture is further optimized through bioinspired Greater Cane Rat Algorithm(GCRA)to improve adaptive learning capabilities.Extensive validation on the Yahoo benchmark indicates state-of-the-art performance,achieving an F1-score of 93.6%(an improvement of 4.5% over baseline VAEs)and a precision of 95.1%.These improvements significantly increase anomaly detection accuracy and robustness,particularly in the AIoT environment,where it effectively handles more complex and dynamic industrial data. 展开更多
关键词 Anomaly detection Time series GCRA CVAE Time-frequency domain
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Multimodal Signal Processing of ECG Signals with Time-Frequency Representations for Arrhythmia Classification 认领 引用 被引量：1
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作者 Yu Zhou Jiawei Tian Kyungtae Kang 《Computer Modeling in Engineering & Sciences》 SCIE EI 2026年第2期990-1017,共28页
Arrhythmias are a frequently occurring phenomenon in clinical practice,but how to accurately dis-tinguish subtle rhythm abnormalities remains an ongoing difficulty faced by the entire research community when conductin... Arrhythmias are a frequently occurring phenomenon in clinical practice,but how to accurately dis-tinguish subtle rhythm abnormalities remains an ongoing difficulty faced by the entire research community when conducting ECG-based studies.From a review of existing studies,two main factors appear to contribute to this problem:the uneven distribution of arrhythmia classes and the limited expressiveness of features learned by current models.To overcome these limitations,this study proposes a dual-path multimodal framework,termed DM-EHC(Dual-Path Multimodal ECG Heartbeat Classifier),for ECG-based heartbeat classification.The proposed framework links 1D ECG temporal features with 2D time–frequency features.By setting up the dual paths described above,the model can process more dimensions of feature information.The MIT-BIH arrhythmia database was selected as the baseline dataset for the experiments.Experimental results show that the proposed method outperforms single modalities and performs better for certain specific types of arrhythmias.The model achieved mean precision,recall,and F1 score of 95.14%,92.26%,and 93.65%,respectively.These results indicate that the framework is robust and has potential value in automated arrhythmia classification. 展开更多
关键词 Electrocardiogram arrhythmia classification multimodal time-frequency representation
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Dominant frequency response and dynamic mechanism of rock slopes under blasting loads:A machine learning-driven time-frequency analysis 认领 引用
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作者 MA Ke PENG Yilin +2 位作者 LIAO Zhiyi LUO Longlong HUANG Yinglu 《Journal of Mountain Science》 SCIE CSCD 2026年第3期1334-1354,共21页
Understanding how rock slopes respond to blasting loads is crucial for maintaining excavation safety and slope stability.Nevertheless,the spatiotemporal evolution,nonlinear dependence on blasting parameters,and predic... Understanding how rock slopes respond to blasting loads is crucial for maintaining excavation safety and slope stability.Nevertheless,the spatiotemporal evolution,nonlinear dependence on blasting parameters,and predictive behavior of dominant frequency responses in slope vibrations remain insufficiently understood and quantified.This study combines time-frequency analysis with machine learning to explore how the dominant frequency(fd)evolves in slopes under blasting.Continuous Wavelet Transform(CWT)was employed to characterize the temporal-frequency evolution of vibration signals,revealing that the dominant frequency exhibits strong spatial dependence and nonlinear variability influenced by blasting parameters and rock mass structures.Three machine learning models,namely Back Propagation Neural Network(BP),Support Vector Machine(SVM),and Random Forest(RF),were developed to predict fd based on 1,000 monitoring samples obtained from numerical and field simulations.Among them,the RF model achieved the highest prediction accuracy,with mean absolute percentage errors(MAPE)below 15%,demonstrating strong robustness and generalization capability.Our analysis shows that external excitation factors,especially the loading frequency(fd),mainly control the frequency response,while internal controlling factors,such as spatial position,lithological variation,and mechanical heterogeneity,modulate localized frequency amplification and energy redistribution.The results reveal that fd tends to decrease with elevation and distance from the blasting source,whereas structural planes and weathered zones induce high-frequency amplification due to scattering and modal coupling effects.This study offers a new framework combining time-frequency analysis and machine learning to measure the nonlinear interaction between blasting and rock mass response,offering new insights for dynamic stability evaluation and hazard mitigation in complex rock slope systems. 展开更多
关键词 Blasting vibration Time-frequency domain analysis Machine learning Dominant frequency
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Advances in time-frequency based geopotential determination 认领 引用
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作者 Heping Sun Wenbin Shen +5 位作者 Kelin Gao Yuping Gao Mingqiang Hou Lifeng Bao Pengfei Zhang Ziyu Shen 《Geodesy and Geodynamics》 EI CSCD 2026年第1期12-24,共13页
The state-of-the-art optical atomic clocks and the time-frequency signal transmission open a fresh field for gravity potential(geopotential)determination.Various methods,including optical fiber frequency transfer,sate... The state-of-the-art optical atomic clocks and the time-frequency signal transmission open a fresh field for gravity potential(geopotential)determination.Various methods,including optical fiber frequency transfer,satellite two-way,satellite common-view,satellite carrier phase,VLBI,tri-frequency combination,and dual-frequency combination,were developed to determine the geopotential differences using optical atomic clocks and then determine the geopotential at station B based on the geopotential at station A.This review elaborates the principles,methods,scientific objectives,applications,and relevant research trends of geopotential determination based on time-frequency signals. 展开更多
关键词 General relativity Geopotential Time-frequency signal transmission techniques Orthometric height Optical clock
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A Method for Detecting Spatio-Temporal Correlation Anomalies of WSN Nodes Based on Topological Information Enhancement and Time-Frequency Feature Extraction 认领 引用
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作者 Miao Ye Ziheng Wang +4 位作者 Qiuxiang Jiang Xingsi Xue Wenxi Liu Yu Ning Cheng Zhu 《Computers, Materials & Continua》 SCIE EI 2026年第8期1840-1870,共31页
In recent years,anomaly detection in Wireless Sensor Networks(WSNs)has been widely studied using Graph Neural Networks and Transformer-based methods.However,in multi-node and multi-modal data scenarios,these approache... In recent years,anomaly detection in Wireless Sensor Networks(WSNs)has been widely studied using Graph Neural Networks and Transformer-based methods.However,in multi-node and multi-modal data scenarios,these approaches still face challenges such as insufficient extraction of spatiotemporal correlation features,limited modeling capabilities when relying solely on either time-domain or frequency-domain information,and high computational overhead.To address these issues,this work aims to develop an anomaly detection model that balances detection performance with computational efficiency,enabling effective identification of complex anomaly patterns.Specifically,we propose a time–frequency feature extraction method with topological information enhancement,topology-enhanced multi-modal spatio-temporal anomaly detection(TE-MSTAD).Building upon the Receptance Weighted Key Value(RWKV)model with linear complexity,a cross-modal feature extraction module is introduced to strengthen the modeling of multi-modal correlations.Meanwhile,adaptive adjacency matrices are constructed by integrating time–frequency features and combining outputs from different Graph Neural Networks,thereby enhancing topological information.Furthermore,a dual-branch structure is designed to jointly model time-domain and frequency-domain features,improving the extraction of complex anomaly characteristics.Experiments on both publicly available datasets and real-world collected data demonstrate that the proposed method achieves F1-scores of 92.52%and 93.28%,respectively,outperforming existing methods in detection performance and generalization capability. 展开更多
关键词 Wireless sensor networks anomaly detection time-frequency domain fusion graph neural networks information enhancement
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Study on the aided PC-ASCL decoding algorithm based on optimized parity check codes 认领 引用
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作者 Jianguo YUAN Deyi YANG +1 位作者 Ziliang ZHU Jinneng XIANG 《Optoelectronics Letters》 EI 2026年第2期87-91,共5页
Aiming at the poor performance of the parity check(PC) aided adaptive successive cancellation list(PC-ASCL) decoding algorithm because the PC code in the polar code can only verify odd errors, an optimized parity chec... Aiming at the poor performance of the parity check(PC) aided adaptive successive cancellation list(PC-ASCL) decoding algorithm because the PC code in the polar code can only verify odd errors, an optimized parity check(OPC) code which can verify all odd errors as well as the half even errors is proposed. The OPC code is used to improve the PC-ASCL decoding algorithm, thus an OPC aided ASCL(OPC-ASCL) decoding algorithm is proposed. In the coding stage, the algorithm divides the information sequence into multiple segments, and places an OPC code at the end of each segment to verify the current information sequence, and places a cyclic redundancy check code at the end of the entire information sequence to verify the entire information sequence. In the decoding stage, the algorithm uses the OPC-ASCL decoder to decode. Simulation results show that compared to the PC-ASCL decoding algorithm, the OPC-ASCL decoding algorithm can reduce the complexity and obtain the certain performance gain. 展开更多
关键词 pc ascl decoding pc code adaptive successive cancellation list pc ascl divides information sequence multip parity check polar code optimized parity check coding stage
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A high-resolution time-frequency analysis tool for fault diagnosis of rotating machinery 认领 引用
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作者 Gang Yu Zhenghao Cui 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2026年第1期145-154,共10页
Fault features in mechanical systems often manifest as transient impulses,which can be effectively analyzed using time-frequency analysis(TFA)methods.Recently,a new TFA technique known as the time-reassigned multi-syn... Fault features in mechanical systems often manifest as transient impulses,which can be effectively analyzed using time-frequency analysis(TFA)methods.Recently,a new TFA technique known as the time-reassigned multi-synchrosqueezing transform(TMssT)was proposed to capture these transient impulses for fault diagnosis.However,the TMSST,which is based on the short-time Fourier transform(STFT),suffers from unclear high-frequency re-presentations owing to the fixed sliding window used in the STFT.To address this limitation,the current study combined TMSST with the S-transform and a local maximum method to enhance the time-frequency representation for improved signal analysis.Furthermore,an extractive reconstruction algorithm that binds the maximum value of the spectral envelope is proposed for spectral decomposition.To validate the proposed technique,a simulated noise-added signal and four experimental bearing defect datasets were used.The results demonstrate that the proposed technique can effectively and accurately extract fault features from bearing signals regardless of whether the bearings operate under constant or varying speed conditions.This study offers a novel and efficient approach for fault diagnosis in mechanical systems with complex dynamic behaviors. 展开更多
关键词 Time-frequency analysis S-transform Extractive reconstruction algorithm Mechanical systems
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Robust connectivity in time-frequency dual fading channels for the 6G satellite IoT:chirp and FRFT 认领 引用
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作者 Wenliang Lin Xinghao Cao +6 位作者 Ke Wang Zhongliang Deng Yishan He Kejia Cui Yaohua Deng Da Wan Zhiwei He 《Digital Communications and Networks》 SCIE EI CSCD 2026年第2期375-387,共13页
With the development of Sixth-Generation(6G)mobile communication technologies,Low Earth Orbit(LEO)satellite communication systems have become extremely important in mobile communications owing to their large coverage,... With the development of Sixth-Generation(6G)mobile communication technologies,Low Earth Orbit(LEO)satellite communication systems have become extremely important in mobile communications owing to their large coverage,high efficiency,and low cost.However,the high dynamic LEO satellite channels cause serious time-frequency dual selective fading,significantly impairing the performance of conventional single time or frequency domain synchronization algorithms and limiting their applicability.To address these challenges,this paper proposes a synchronization algorithm based on Linear Frequency Modulation(LFM)signals and the Fractional Fourier Transform(FRFT).Exploiting the inherent robustness of LFM signals against frequency deviations and multipath effects,coupled with their energy concentration property in the optimal fractional Fourier domain,the proposed algorithm enables efficient synchronization with enhanced resilience to time-frequency variations.Furthermore,LFM preamble sequences are optimally designed for diverse channel conditions.This work presents a theoretical analysis of the time-frequency nonstationary characteristics of LEO satellite channels and discusses the performance limitations of traditional synchronization algorithms.The proposed integrated FRFTLFM synchronization framework and sequence optimization scheme are rigorously evaluated via comprehensive simulations.The results demonstrate substantial improvements in synchronization accuracy and computational efficiency compared with conventional methods,particularly under time-frequency dual selective fading LEO satellite channels.The algorithm provides a robust and reliable solution for time-frequency synchronization in LEO satellite communication systems,thereby enhancing overall system performance and reliability. 展开更多
关键词 Time-frequency synchronization Linear frequency modulation Fractional fourier transform Low earth orbit satellite communications Nonstationary channel
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Quantum toric code decoding method based on syndrome-preliminary error fusion module and ResNet architecture 认领 引用
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作者 Nai-Hua Ji Ping-Li Song +2 位作者 Wei Wang Hui-Qian Sun Hong-Yang Ma 《Chinese Physics B》 SCIE EI CAS CSCD 2026年第6期649-659,共11页
Quantum error correction technology is based on the principle of redundant encoding,encoding logical quantum information into multiple physical qubits to provide important support for the stable operation of quantum c... Quantum error correction technology is based on the principle of redundant encoding,encoding logical quantum information into multiple physical qubits to provide important support for the stable operation of quantum computers.To address the issues of low decoding accuracy and limited feature extraction in quantum error correction,this paper proposes a toric code decoder based on a syndrome-preliminary error fusion module(SPEFM)and a ResNet architecture.This decoder takes full advantage of the correlations between X and Z errors.In the SPEFM,the syndrome and preliminary error predictions are deeply fused,while a unidirectional Swin transformer architecture is incorporated to extract global error features from the syndrome data,signiffiificantly improving both decoding accuracy and computational efffiificiency.In addition,this paper further extracts local error features from the fused features using the deep residual structure of ResNet,enhancing the decoder's ability to capture quantum error patterns.Experimental results show that the decoder is applicable to different code distances(d=4,6,8,10)under the depolarizing noise model.Its bit error rate is lower than that of the minimum weight perfect matching(MWPM)algorithm,and its logical error rate is lower than both the MWPM algorithm and the ResNet18 decoder.Furthermore,the decoding threshold is increased to 0.163,representing a 3.82%improvement over the MWPM algorithm threshold of 0.157. 展开更多
关键词 quantum error correction toric code ResNet Swin transformer
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Two Bit-Serial Architectures for Check Node Update in Min-Sum Decoding of LDPC Codes 认领 引用
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作者 Hu Qing He Xuan +2 位作者 Luo Lisha Cai Kui Tang Xiaohu 《China Communications》 SCIE EI CSCD 2026年第3期142-150,共9页
Implementing check node(CN)update based on the minimum value(MV)and second MV of incoming message magnitudes is crucial for Min-Sum Algorithms(MSAs).In the category of bit-serial implementations,existing schemes suffe... Implementing check node(CN)update based on the minimum value(MV)and second MV of incoming message magnitudes is crucial for Min-Sum Algorithms(MSAs).In the category of bit-serial implementations,existing schemes suffer from decoding performance degradation,large hardware areas,and/or long latency.In this paper,we propose two efficient CN update functions based on the MV and an approximate second MV,and design bit-serial architectures to implement them.Simulation results show that our functions exhibit the minimum decoding performance degradation compared to the existing functions using approximate second MVs.Moreover,the applicationspecific integrated circuits(ASIC)implementation results demonstrate the advantages of our architectures in terms of area,latency,etc. 展开更多
关键词 bit-serial check node update hardware implementation LDPC code min-sum algorithm
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A Comparative Study Between SDP-CNN and Time-Frequency-CNN-Based Approaches for Fault Detection 认领 引用
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作者 Mario Spirto Francesco Melluso +4 位作者 Armando Nicolella Pierangelo Malfi Chiara Cosenza Sergio Savino Vincenzo Niola 《Journal of Dynamics, Monitoring and Diagnostics》 2026年第1期25-37,共13页
The image-based approach is widely used in fault detection(FD)algorithms of mechanical systems.The images are derived from the vibrational signals transformed from the time to time–frequency domain,and they are used ... The image-based approach is widely used in fault detection(FD)algorithms of mechanical systems.The images are derived from the vibrational signals transformed from the time to time–frequency domain,and they are used to develop a convolutional neural network(CNN)to automate the FD process.Nowadays,images are also obtained from the transformation of vibrational signals from the time domain to symmetrized dot pattern(SDP)coordinates,achieving high CNN testing accuracy.This paper shows a comparison of image-CNN approaches for FD using images obtained from time–frequency transforms and those obtained from the SDP transform as input.The comparison was conducted using experimental data from two publicly available bearing datasets,examining both the accuracy of the CNNs and the computational time required for the vibrational signal transformations.The results show that the SDP-CNN approach achieves the same accuracy as spectrogram-CNN approaches but with a significantly reduced computational time.These results support the future real-time implementation of the SDPCNN approach for FD in mechanical systems such as bearings. 展开更多
关键词 ball bearings CNN fault detection symmetrized dot pattern time-frequency analysis
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Multi-Attempt List Decoding of Polar Codes 认领 引用
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作者 Yuan Peihong Chen Zhe +1 位作者 Wu Yongpeng Gao Yue 《China Communications》 SCIE EI CSCD 2026年第4期27-36,共10页
In this work,we propose a multi-attempt successive cancellation list(MA-SCL)decoder for polar codes that achieves identical error-correction performance to standard SCL decoding while reducing average complexity.Unlik... In this work,we propose a multi-attempt successive cancellation list(MA-SCL)decoder for polar codes that achieves identical error-correction performance to standard SCL decoding while reducing average complexity.Unlike CRC-aided SCL,the proposed MA-SCL progressively restarts decoding with increasing list sizes and reuses information from previous attempts.This design eliminates the need for outer CRC codes.The decoder features dynamic searchspace pruning and an early stopping criterion based on path metrics.Simulations show MA-SCL matches SCL performance with lower average complexity,particularly for short polar-like codes with reed-muller(RM)rate profiles and dynamic frozen constraints.Compared to existing adaptive decoders,MA-SCL offers implementation advantages by eliminating the need for stack-/heap management while providing relatively stable latency bounds(1×to|Λ|×SCL latency). 展开更多
关键词 complexity-adaptive decoding list decoding polar coding
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Advanced High-Order Graph Convolutional Networks With Assorted Time-Frequency Transforms 认领 引用
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作者 Ling Wang Ye Yuan Xin Luo 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2026年第2期394-408,共15页
A dynamic graph(DG)is adopted to portray the evolving interplay between nodes in real-world scenarios prevalently.A high-order graph convolutional network(HGCN)is equipped with the ability to represent a DG by the spa... A dynamic graph(DG)is adopted to portray the evolving interplay between nodes in real-world scenarios prevalently.A high-order graph convolutional network(HGCN)is equipped with the ability to represent a DG by the spatial-temporal message passing mechanism built on tensor product.Concretely,an HGCN utilizes the discrete Fourier transform(DFT)to implement temporal message passing and then employs face-wise product to realize spatial message passing.However,DFT is only a special case of assorted time-frequency transforms,which considers the complex temporal patterns partially,thereby resulting in an inaccurate temporal message passing possibly.To address this issue,this study proposes six advanced time-frequency transform-incorporated HGCNs(TF-HGCNs)with discrete Fourier,discrete Hartley,discrete cosine,Haar wavelet,Walsh Hadamard,and slant transforms.In addition,a potent ensemble is built regarding the proposed six TF-HGCNs as the bases.Finally,the corresponding theoretical proof is presented.Empirical studies on six DG datasets demonstrate that owing to diverse time-frequency transforms,the proposed six TF-HGCNs significantly outperform state-of-the-art models in addressing the task of link weight estimation.Moreover,their ensemble outstrips each base's performance. 展开更多
关键词 Dynamic graph(DG)learning ensemble graph representation learning high-order graph convolution network(HGCN) time-frequency transform tensor product
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Adaptive Coding and Modulation Using Enhanced Turbo Codes for Meteor Burst Communication 认领 引用
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作者 Ding Mengchuan Li Zhiyong +1 位作者 Wang Wei Li Xuekun 《China Communications》 SCIE EI CSCD 2026年第5期1-14,共14页
Meteor burst channels(MBC)exhibit significant randomness and non-stationarity,limiting the effectiveness of traditional fixed-rate transmission strategies.This paper proposes an adaptive coding and modulation(ACM)sche... Meteor burst channels(MBC)exhibit significant randomness and non-stationarity,limiting the effectiveness of traditional fixed-rate transmission strategies.This paper proposes an adaptive coding and modulation(ACM)scheme based on real-time channel state perception using enhanced Turbo codes.By leveraging the interleaving structure of Turbo codes to mitigate channel fading and incorporating multi-rate adaptation,the scheme dynamically adjusts symbol rate,modulation,and coding methods to improve spectral efficiency.Meanwhile,a joint evaluation mechanism integrating physical-layer signal to noise ratio(SNR)estimation and media access control(MAC)-layer frame error rate(FER)statistics is introduced to achieve dynamic optimization of switching thresholds in multipath channels.Simulation and experimental results demonstrate that the proposed scheme significantly enhances system adaptability to MBC,and increases data transmission success rates,offering a more efficient and reliable solution for MBC systems. 展开更多
关键词 ACM enhanced turbo codes MAC-layer meteor burst channels
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Rethink delay Doppler channels and time-frequency coding 认领 引用
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作者 Xiang-Gen Xia 《Journal of Information and Intelligence》 2025年第3期189-193,共5页
In this paper,we rethink delay Doppler channels(also called doubly selective channels).We prove that no modulation schemes(including the current active VOFDM/OTFS)can compensate a non-trivial Doppler spread well.We th... In this paper,we rethink delay Doppler channels(also called doubly selective channels).We prove that no modulation schemes(including the current active VOFDM/OTFS)can compensate a non-trivial Doppler spread well.We then discuss some of the existing methods to deal with time-varying channels,in particular time-frequency(TF)coding in an OFDM system.TF coding is equivalent to space-time coding in the math part.We also summarize state of the art on space-time coding that was an active research topic over a decade ago. 展开更多
关键词 Orthogonal frequency division multiplexing(OFDM) Vector orthogonal frequency-division multiplexing(VOFDM) Orthogonal time frequency space(OTFS) Delay Doppler channel Spaceime/frequency coding
Construction of time-frequency codes based on protograph LDPC codes in OFDM communication systems 认领 引用 被引量：2
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作者 Kaiyao Wang Yang Xiao Kiseon Kim 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2012年第3期335-341,共7页
This paper proposes a scheme to construct time- frequency codes based on protograph low density parity check （LDPC） codes in orthogonal frequency division multiplexing （OFDM） communication systems. This approach s... This paper proposes a scheme to construct time- frequency codes based on protograph low density parity check （LDPC） codes in orthogonal frequency division multiplexing （OFDM） communication systems. This approach synthesizes two techniques： protograph LDPC codes and OFDM. One symbol of encoded information by protograph LDPC codes corresponds to one sub-carrier, namely the length of encoded information equals to the number of sub-carriers. The design of good protograph LDPC codes with short lengths is given, and the proposed proto- graph LDPC codes can be of fast encoding, which can reduce the encoding complexity and simplify encoder hardware implementa- tion. The proposed approach provides a higher coding gain in the Rayleigh fading channel. The simulation results in the Rayleigh fading channel show that the bit error rate （BER） performance of the proposed time-frequency codes is as good as random LDPC- OFDM codes and is better than Tanner LDPC-OFDM codes under the condition of different fading coefficients. 展开更多
关键词 time-frequency code protograph low density parity check （LDPC） code orthogonal frequency division multiplexing （OFDM） fast encoding algorithm.
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Abnormal Signal Recognition with Time-Frequency Spectrogram:A Deep Learning Approach 认领 引用
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作者 Kuang Tingyan Chen Huichao +3 位作者 Han Lu He Rong Wang Wei Ding Guoru 《China Communications》 SCIE EI CSCD 2025年第11期305-319,共15页
With the increasingly complex and changeable electromagnetic environment,wireless communication systems are facing jamming and abnormal signal injection,which significantly affects the normal operation of a communicat... With the increasingly complex and changeable electromagnetic environment,wireless communication systems are facing jamming and abnormal signal injection,which significantly affects the normal operation of a communication system.In particular,the abnormal signals may emulate the normal signals,which makes it very challenging for abnormal signal recognition.In this paper,we propose a new abnormal signal recognition scheme,which combines time-frequency analysis with deep learning to effectively identify synthetic abnormal communication signals.Firstly,we emulate synthetic abnormal communication signals including seven jamming patterns.Then,we model an abnormal communication signals recognition system based on the communication protocol between the transmitter and the receiver.To improve the performance,we convert the original signal into the time-frequency spectrogram to develop an image classification algorithm.Simulation results demonstrate that the proposed method can effectively recognize the abnormal signals under various parameter configurations,even under low signal-to-noise ratio(SNR)and low jamming-to-signal ratio(JSR)conditions. 展开更多
关键词 abnormal signal recognition deep learning time-frequency analysis
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Computation-Efficient Decoding of LDPC Codes for High-Speed Space Laser Communications 认领 引用
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作者 Hu Zhuojun Chen Zhao +1 位作者 Kuang Linling Yin Liuguo 《China Communications》 SCIE EI CSCD 2025年第12期108-123,共16页
Space laser communication(SLC)is an emerging technology to support high-throughput data transmissions in space networks.In this paper,to guarantee the reliability of high-speed SLC links,we aim at practical implementa... Space laser communication(SLC)is an emerging technology to support high-throughput data transmissions in space networks.In this paper,to guarantee the reliability of high-speed SLC links,we aim at practical implementation of low-density paritycheck(LDPC)decoding under resource-restricted space platforms.Particularly,due to the supply restriction and cost issues of high-speed on-board devices such as analog-to-digital converters(ADCs),the input of LDPC decoding will be usually constrained by hard-decision channel output.To tackle this challenge,density-evolution-based theoretical analysis is firstly performed to identify the cause of performance degradation in the conventional binaryinitialized iterative decoding(BIID)algorithm.Then,a computation-efficient decoding algorithm named multiary-initialized iterative decoding with early termination(MIID-ET)is proposed,which improves the error-correcting performance and computation efficiency by using a reliability-based initialization method and a threshold-based decoding termination rule.Finally,numerical simulations are conducted on example codes of rates 7/8 and 1/2 to evaluate the performance of different LDPC decoding algorithms,where the proposed MIID-ET outperforms the BIID with a coding gain of 0.38 dB and variable node calculation saving of 37%.With this advantage,the proposed MIID-ET can notably reduce LDPC decoder’s hardware implementation complexity under the same bit error rate performance,which successfully doubles the total throughput to 10 Gbps on a single-chip FPGA. 展开更多
关键词 computation-efficient decoding highspeed decoders LDPC codes LLR initialization space laser communications
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Low Complexity Successive Cancellation List Decoding of U-UV Codes 认领 引用
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作者 Chen Wenhao Chen Li +1 位作者 Lin Jingyu Zhang Huazi 《China Communications》 SCIE EI CSCD 2025年第1期41-60,共20页
Constituted by BCH component codes and its ordered statistics decoding(OSD),the successive cancellation list(SCL)decoding of U-UV structural codes can provide competent error-correction performance in the short-to-med... Constituted by BCH component codes and its ordered statistics decoding(OSD),the successive cancellation list(SCL)decoding of U-UV structural codes can provide competent error-correction performance in the short-to-medium length regime.However,this list decoding complexity becomes formidable as the decoding output list size increases.This is primarily incurred by the OSD.Addressing this challenge,this paper proposes the low complexity SCL decoding through reducing the complexity of component code decoding,and pruning the redundant SCL decoding paths.For the former,an efficient skipping rule is introduced for the OSD so that the higher order decoding can be skipped when they are not possible to provide a more likely codeword candidate.It is further extended to the OSD variant,the box-andmatch algorithm(BMA),in facilitating the component code decoding.Moreover,through estimating the correlation distance lower bounds(CDLBs)of the component code decoding outputs,a path pruning(PP)-SCL decoding is proposed to further facilitate the decoding of U-UV codes.In particular,its integration with the improved OSD and BMA is discussed.Simulation results show that significant complexity reduction can be achieved.Consequently,the U-UV codes can outperform the cyclic redundancy check(CRC)-polar codes with a similar decoding complexity. 展开更多
关键词 ordered statistics decoding successive cancellation list decoding U-UV codes
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Neural network-based decoding for bias-tailored quantum codes over quantum channels with asymmetric noise 认领 引用
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作者 Jihao Fan Qianhui Zhang +1 位作者 Zhihua Zhang Jun Li 《Communications in Theoretical Physics》 SCIE CAS CSCD 2025年第12期32-42,共11页
To improve the decoding performance of quantum error-correcting codes in asymmetric noise channels,a neural network-based decoding algorithm for bias-tailored quantum codes is proposed.The algorithm consists of a bias... To improve the decoding performance of quantum error-correcting codes in asymmetric noise channels,a neural network-based decoding algorithm for bias-tailored quantum codes is proposed.The algorithm consists of a biased noise model,a neural belief propagation decoder,a convolutional optimization layer,and a multi-objective loss function.The biased noise model simulates asymmetric error generation,providing a training dataset for decoding.The neural network,leveraging dynamic weight learning and a multi-objective loss function,mitigates error degeneracy.Additionally,the convolutional optimization layer enhances early-stage convergence efficiency.Numerical results show that for bias-tailored quantum codes,our decoder performs much better than the belief propagation(BP)with ordered statistics decoding(BP+OSD).Our decoder achieves an order of magnitude improvement in the error suppression compared to higher-order BP+OSD.Furthermore,the decoding threshold of our decoder for surface codes reaches a high threshold of 20%. 展开更多
关键词 quantum error correction quantum channels asymmetric noise neural networkbased decoding bias-tailored quantum codes
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