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Adaptive Bistable Stochastic Resonance Based Weak Signal Reception in Additive Laplacian Noise

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China Communications 2024年第1期21卷 228-241页

作者： Jin liu zan li Qiguang Miao li Yang School of Computer Science and Technology Xidian UniversityXi’an 710071China State Key Laboratory of Integrated Services Networks Xidian UniversityXi’an 710071China

Weak signal reception is a very important and challenging problem for communication systems especially in the presence of non-Gaussian noise,and in which case the performance of optimal linear correlated receiver degrades *** at this,a novel uncorrelated reception scheme based on adaptive bistable stochastic resonance(ABSR)for a weak signal in additive Laplacian noise is *** analyzing the key issue that the quantitative cooperative resonance matching relationship between the characteristics of the noisy signal and the nonlinear bistable system,an analytical expression of the bistable system parameters is *** this basis,by means of bistable system parameters self-adaptive adjustment,the counterintuitive stochastic resonance(SR)phenomenon can be easily generated at which the random noise is changed into a benefit to assist signal ***,it is demonstrated that approximately 8dB bit error ratio(BER)performance improvement for the ABSR-based uncorrelated receiver when compared with the traditional uncorrelated receiver at low signal to noise ratio(SNR)conditions varying from-30dB to-5dB.

关键词： adaptive bistable stochastic resonance additive Laplacian noise low signal to noise ratio uncorrelated reception scheme weak signal reception

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面向无人机载平台的轻量级小目标检测算法

河南大学学报(自然科学版) 2025年第1期 1-11页

作者：党兰学李赞苗长伟崔金华赵雅靓河南大学河南省大数据分析与处理重点实验室河南开封475004 中核勘察设计研究有限公司郑州475000 华中科技大学计算机与信息工程学院武汉430074 河南大学计算机与信息工程学院河南开封475004

无人机载平台中的目标检测在军事和民用领域具有重要的应用价值.然而,现有的检测方法通常侧重于多尺度目标检测,缺乏对小目标的优化,且模型复杂度过高,难以在资源受限的机载平台中应用.为此,本文提出了一种面向无人机载平台的轻量级小... 详细信息

无人机载平台中的目标检测在军事和民用领域具有重要的应用价值.然而,现有的检测方法通常侧重于多尺度目标检测,缺乏对小目标的优化,且模型复杂度过高,难以在资源受限的机载平台中应用.为此,本文提出了一种面向无人机载平台的轻量级小目标检测算法YOLOH(You Only Look One Head).首先,针对小目标对基准网络优化,移除深层特征以减少模型参数量,增加浅层特征以获取小目标信息.其次,在特征融合部分加入NAM注意力,增强对小目标的感知能力.接着,设计了多感受野聚焦模块MRFF,以挖掘特征图的感受野信息,增强模型的多尺度检测能力.最后,使用LAMP算法对模型剪枝,去除冗余神经元以压缩模型.实验结果表明,与YOLOv8s相比,YOLOH的模型参数量和计算量分别减少了92%和35%,FPS提高了57%.在VisDrone2019和CARPK数据集上AP_(S)分别提高了3.3%和3.7%.与其他轻量级模型相比,所提YOLOH具有最佳的整体性能,同时平衡了模型大小、精度和推理速度,为无人机载平台的目标检测提供了有效的解决方案.

关键词：机载平台 YOLOH 小目标检测轻量级多感受野

Generation and characterization of orthogonal FH sequences for the cognitive network

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Science China(Information Sciences) 2015年第2期58卷 140-150页

作者： GUAN Lei li zan SI JiangBo HUANG YangChao State Key Laboratory of Integrated Services Networks Xidian University

The existing orthogonal frequency hopping(FH) sequence cannot support the high throughput and high spectrum efficient cognitive FH(CFH) network due to its small family size, high computational complexity and short period. To overcome these disadvantages, this paper investigates the generation of the orthogonal FH sequence and analyzes its multiple accessibility performance based on the CFH frequency division multipleaccess(FDMA) network model. By the random mapping and cyclical shift replacement(CSR) scheme, a large family size of orthogonal FH sequence with dynamic frequency slot number is generated. In this case, the external interference could be eliminated by avoiding the interfered frequencies, and blocking mutual interference incurred for the packet by the orthogonal frequencies. Moreover, the theoretical relationships of the throughput and transmission delay with respect to the user number and the packet arrival rate are given, which shows that our proposed orthogonal FH sequence could support high throughput and short packet transmission delay in CFH-FDMA network. The simulation results validate our theoretical analysis of the CFH-FDMA network performance, and show that our proposed sequence outperforms the widely used no hit zone FH sequences in terms of uniformity, randomness, Hamming correlation, complexity and sensitivity, etc.

关键词： cognitive frequency hopping orthogonal frequency hopping sequence frequency hopping network frequency division multiple access throughput

Method of neural network modulation recognition based on clustering and Polak-Ribiere algorithm

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Journal of Systems Engineering and Electronics 2014年第5期25卷 742-747页

作者： Faquan Yang zan li Hongyan li Haiyan Huang Zhongxian Pan State Key Laboratory of Integrated Service Networks Xidian University School of Electrical and Information Engineering Foshan University

To improve the recognition rate of signal modulation recognition methods based on the clustering algorithm under the low SNR, a modulation recognition method is proposed. The characteristic parameter of the signal is extracted by using a clustering algorithm, the neural network is trained by using the algorithm of variable gradient correction （Polak-Ribiere） so as to enhance the rate of convergence, improve the performance of recognition under the low SNR and realize modulation recognition of the signal based on the modulation system of the constellation diagram. Simulation results show that the recognition rate based on this algorithm is enhanced over 30% compared with the methods that adopt clustering algorithm or neural network based on the back propagation algorithm alone under the low SNR. The recognition rate can reach 90% when the SNR is 4 dB, and the method is easy to be achieved so that it has a broad application prospect in the modulating recognition.

关键词： clustering algorithm feature extraction algorithm of Polak-Ribiere neural network (NN) modulation recognition.

Tradeoffs in Covert Wireless Communication with a Controllable Full-Duplex Receiver

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China Communications 2022年第5期19卷 87-101页

作者： Yue Zhao zan li Danyang Wang Nan Cheng State Key Laboratory of Integrated Service Networks Xidian UniversityXi’an 710071Shaanxi ProvinceChina Collaborative Innovation Center of Information Sensing and Understanding Xi’an 710071Shaanxi ProvinceChina

This paper investigates the tradeoff of the communication link and the eavesdropping link in covert communication in the presence of a full-duplex(FD)*** a warden(Willie)attempts to detect the signal transmitted from a legitimate transmitter(Alice),the controllable FD receiver(Bob)can transmit with random power to impose interference uncertainty to Willie and force it to make an incorrect *** maximize the average transmission rate(ATR)of Alice-Bob and the average covert probability(ACP)for Willie,we propose a multi-objective optimization framework to optimize Bob’s power uncertainty range(PUR)and spatial position jointly,subject to the sufficient condition for covert communication and the none-deployed-zone(NDZ).Due to the presence of multiple optimization objectives and nonconvex constraints,the nondominated sorting genetic algorithm II(NSGA-II)is utilized to explore the Pareto front and to give a set of solutions that reflect tradeoffs between the two conflicting *** results reveal that the solutions determined by the NSGA-II have larger values for both ATR and ACP than the other two *** also show the positive effect of the width of the PUR of Bob on the Pareto front.

关键词： covert communication multi-objective optimization full-duplex resource allocation

OAM-Based Hybrid-Duplex Cognitive Frequency Hopping

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Journal of Communications and Information Networks 2020年第4期5卷 381-392页

作者： liping liang zan li Wenchi Cheng Hailin Zhang State Key Laboratory of Integrated Services Networks Xidian UniversityXi’an 710071China

In cognitive radio networks,the jamming attacks,which have the same ability with secondary users(SUs)but access the licensed channels without considering the carrier sense multiple access protocol,can disguise a primary user(PU)or SU to occupy the licensed channels,thus resulting in failing to access the licensed channels for PUs and *** full/half duplex cognitive frequency hopping(CFH),where users sense the occupancy of licensed channels and then dynamically adjust the hopping parameters,can mitigate the hostile ***,due to the explosive growth of serves and data traffic,it is very difficult to significantly increase the anti-jamming results and achieve high capacities with full/half duplex CFH for both PUs and SUs in cognitive radio *** achieve efficient anti-jamming and high capacities for PUs and SUs,in this paper we propose the orbital angular momentum(OAM)-based hybrid-duplex CFH scheme,which jointly uses the half-duplex cooperative sensing and full-duplex transmission modes for PUs and SUs in cognitive radio *** the OAM-based hybrid-duplex CFH scheme,PUs and SUs can identify the occupancy of licensed channels with half-duplex fashion,thus significantly reducing the probability of signals ***,based on the sensing results,the signals are allowed to be transmitted and received by the same time-slots,carrier frequencies,and *** average capacities of PUs and SUs are derived,*** numerical results show that our proposed OAM-based hybrid-duplex CFH scheme can significantly increase the capacities of PUs and SUs in cognitive radio networks under hostile jamming attacks.

关键词： orbital angular momentum(OAM) hybrid duplex cognitive frequency hopping cognitive radio net-works anti-jamming

Secure NOMA and OMA coordinated transmission schemes in untrusted relay networks

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Science China(Information Sciences) 2021年第10期64卷 266-267页

作者： Lu LV zan li Haiyang DING Jian CHEN State Key Laboratory of Integrated Services Networks Xidian University National Mobile Communications Research Laboratory Southeast University School of Information and Communications National University of Defense Technology

Dear editor,Safeguarding physical-layer non-orthogonal multiple access(NOMA) transmissions using relays has been received widespread attention [1, 2]. However, a relay may be datalevel untrusted and serve as an eavesdropper to decode its forwarded messages. Hence, information security needs to be guaranteed if an untrusted relay is involved.

关键词： Information Systems and Communication Service

Effective bias reduction methods for passive source localization using TDOA and GROA

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Science China(Information Sciences) 2013年第7期56卷 97-108页

作者： HAO BenJian li zan QI PeiHan GUAN Lei State Key Laboratory of Integrated Services Networks Xidian University

For passive source localization based on both TDOA and GROA, this paper proposes two bias reduction methods for the well-known Weighted-Least-Squares (WLS) estimator. We first derive the passive source localization bias from the two-step algebraic closed-form solution. This bias is found to be considerably larger than the Maximum likelihood Estimator (MLE) and limits the WLS estimator's practical applications. In this paper, We develop two methods to reduce the bias. The first one called Bias-Subtraction-Method (BSM) directly subtracts the expected bias from the solution of the WLS estimator, and the second one called Bias-Reduction-Method (BRM) imposes a constraint to the equation error formulation to improve the source location estimate. The noise covariance matrix must be known exactly in calculating the expected bias in BSM, and we only need to know the structure of it in BRM. For far-field sources localization when the noise is Gaussian and not too large, both of the two proposed methods can reduce the localization bias effectively and achieve the Cramér-Rao Lower Bound (CRLB) performance very well, and the BRM almost has the same performance as the MLE estimator. Simulations corroborate the performance of the two proposed methods.

关键词： source localization bias reduction Time Differences of Arrival (TDOA) Gain Ratios of Arrival (GROA) Cramér-Rao Lower Bound (CRLB)

Bistable Stochastic Resonance Enhanced 4-ary PAM Signal Detection under Low SNR

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China Communications 2019年第4期16卷 196-207页

作者： linlin liang Nina Zhang Haiyan Huang zan li School of Telecommunications Engineering Xidian University Xianyang Detachment of Chinese Armed Police Force School of Electronic and Information Engineering Lanzhou Jiaotong University The Collaborative Innovation Center of Information Sensing and Understanding at Xidian University

To boost the performance of 4-ary pulse amplitude modulated(PAM) at low signal-to-noise ratio(SNR), bistable stochastic resonance(BSR) system is introduced into digital communications system and get a reliable signal detection scheme. In this paper, we first analyse BSR system for different amplitudes of 4-ary PAM signals. The steadystate of the bistable system will be statistically distinct, and the feasibility of the proposed detection scheme is confirmed. On this basis, we present a detailed study on steady-state transitions of the BSR system, and an explicit expression of the bistable system parameters is derived. By setting the bistable system parameters, bistable system, 4-ary PAM signal, and noise reach the resonance state, and the BSR-based detection scheme is implemented. Moreover, we derive an analytical expression to calculate the symbol error rate(SER) of 4-ary PAM signals with the BSR-based detection under additive white Gaussian noise(AWGN). Finally, the simulation results validate that BSR-based detection scheme can improve the detection performance while efficiently reducing the symbol error rate.

关键词： 4-ary pulse amplitude modulated signal detection Low SNR Symbol error rate(SER) Bistable stochastic resonance(BSR)