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Combining Radon-ambiguity transform with second-order difference to improve Detection probability of LFM signals in low SNR

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Journal of Systems Engineering and Electronics 2009年第1期20卷 13-19页

作者： Tan Xiaogang Wei Ping Li Liping School of Electronic Engineering Univ. of Electronic Science and Technology of China Chengdu 610054 P. R. China

The Radon-ambiguity transform （RAT）, although efficient for detecting the linear frequency modulated signals （LFMs）, is troubled by the energy accumulation of noise in low signal-to-noise ratio （SNR）. A secondorder difference （SOD） method is proposed to treat with this problem. In the SOD method, the optimal search step and difference step are derived from the LFM rate resolution formula. The sharpness of the peaks of RAT is measured by curvature, and the sharpness, but not the magnitude of the peaks, is used to detect the LFMs. The SOD method removes the noise energy accumulation and reserves the drastically changing components integrally; thus, it improves the Detection probability of LFMs in low SNR. The expected performance of the new method is verified by 100 Monte Carlo simulations.

关键词： linear frequency modulated signals Radon-axnbiguity transform Detection probability low signal-to-noise ratio.

Influence of Range Gate Width on Detection probability and Ranging Accuracy of Single Photon Laser Altimetry Satellite

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Journal of Geodesy and Geoinformation Science 2020年第2期3卷 36-44页

作者： Guoyuan LI Fanghong YE Xinming TANG Dongping XIE Jiapeng HUANG Genhua HUANG Land Satellite Remote Sensing Application Center Ministry of Natural ResourcesBeijing 100048China School of Resource and Environmental Sciences Wuhan UniversityWuhan 430079China Key Laboratory of Space Active Opto-electronics Technology Chinese Academy of SciencesShanghai 200038China

The influence of the single photon laser altimeter range-gate width on the Detection probability and ranging accuracy is discussed and analyzed,according to the LiDAR equation,single photon detection equation and the Monte Carlo method to simulate the experiment.The simulated results show that the probability of detection is not affected by the range gate,while the probability of false alarm is relative to the gate width.When the gate width is 100 ns,the ranging accuracy can accord with the requirements of satellite laser altimeter.But when the range gate width exceeds 400 ns,ranging accuracy will decline sharply.The noise ratio will be more as long as the range gate to get larger,so the refined filtering algorithm during the data processing is important to extract the useful photons effectively.In order to ensure repeated observation of the same point for 25 times,we deduce the quantitative relation between the footprint size,footprint,and frequency repetition according to the parameters of ICESat-2.The related conclusions can provide some references for the design and the development of the domestic single photon laser altimetry satellite.

关键词： satellite laser altimeter range gate ranging accuracy Detection probability monte carlo single photon laser

Analysis of Detection probability and False probability for Laser Detector

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Analysis of Detection Probability and False Probability for ...

Enhanced spectrum sensing using a combination of energy detector,matched filter and cyclic prefix

第二届国际测量仪器与测试自动化学术会议

作者： Ma Jinglan Zhang Yongli Wan Jingsheng (School of Information Engineering Beijing Institute of Petro-chemical Technology Beijing 102617 China)

＜正＞The Detection probability and the false probability are the important indices of overall design for the laser detector. They are also the important parameters for scaling the reliability of the laser detector.The mathematical models for the interrelation of the Detection probability,the false probability,the single-noise ratio and the threshold are built at first in this paper.Then the statistic distributed rules of the detection probabilities and the false probabilities for the pulse system laser detector and the pseudorandom code system laser detector are analyzed using Monte Carlo method.It is seen from the simulation results that the Detection probability is increased greatly and the false probability is reduced for the laser detector using pseudorandom code compared with the laser detector using pulse.It is proved by design and experiments that the theoretic foundation is provided by this method for designing scientifically laser detector.

关键词： proximity detector laser detector Detection probability false probability pseudo-random code

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Digital Communications and Networks 2020年第4期6卷 534-541页

作者： Ghassan Alnwaimi Hatem Boujemaa King Abdulaziz University Saudi Arabia COSIM Lab SUPCOMTunisia

In this paper,we propose a sensing scheme based on energy detection,matched filter and cyclic prefix.Both Equal Gain Combining(EGC)and optimal combination of the aforementioned detectors are investigated in cooperative and non-cooperative spectrum sensing scenarios.In packet transmission systems such as OFDM(Orthogonal Frequency Division Multiple access)systems,the proposed scheme takes advantage of utilizing more samples than individual detectors,i.e.,cyclic prefix,training or pilot samples,and data payload samples.The proposed combine-sensing scheme offers higher Detection probability and lower false alarm probability,as compared with the performance of individual detectors over the same frame duration.Simulation results are congruent with the theoretical curves and confirm the validity of our derivations.

关键词： Cooperative spectrum sensing Energy detector Matched filter Cyclic prefix CFAR CDR Cognitive radio networks False alarm probability Detection probability

A Novel Spectrum Handoff-Based Sensing-Throughput Tradeoff Scheme in Cognitive Radio

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China Communications 2016年第12期13卷 59-68页

作者： Xin Liu Feng Li Weidang Lu School of Information and Communication Engineering Dalian University of Technology College of Information Engneering Zhejiang University of Technology

In cognitive radio(CR), there is a tradeoff between spectrum sensing time and throughput of secondary user(SU). In the conventional sensing-throughput tradeoff scheme, when the presence of the primary user(PU) is detected, the SU will stop forwarding data and wait to redetect the PU in the following frame, yielding great throughput loss. In order to improve the SU's throughput, a novel sensing-throughput tradeoff scheme is proposed, which allows the SU to search for a new idle channel through spectrum searching and transfer to this channel to continue communication, when the presence of the PU is detected. An optimization problem is proposed to maximize the SU's throughput in the proposed scheme through jointly optimizing the sensing time, the searching time and the number of available channels, providing that the Detection probability to the PU is guaranteed. By fixing the number of channels, based on alternating direction optimization, the joint optimization algorithm of sensing time and searching time is proposed, and then the optimal number of channels is obtained through enumerative searching. The simulation results show that there exist the optimal solutions to the proposed scheme, and the proposed scheme outperforms the conventional scheme notably, with different detection probabilities and sampling frequencies.

关键词： cognitive radio energy sensing throughput sampling frequency Detection probability

High Capacity Spectrum Sensing Framework Based on Relay Cooperation

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China Communications 2016年第8期13卷 117-126页

作者： Wu Xuanli Han Xingling Fabrice Labeau School of Electronic and Information Engineering Harbin Institute of Technology Harbin 150001 China Department of Electrical and Computer Engineering McGill University Quebec Canada

In order to reduce interference to primary users and provide better performance of Detection probability and channel capacity in multi-user cooperative spectrum sensing networks, a high capacity spectrum sensing framework is proposed based on the analysis of amplification factors on the performance of Detection probability and channel capacity. Thanks to the energy concentration property of chirp signals in the Fractional Fourier Transform(Fr FT) domain, sinusoidal signal and different chirp signals are utilized for primary user and cognitive users, respectively. Hence, spectrum sensing and signal transmission can be performed simultaneously in our proposed framework. Simulation results show that compared with the previous relay-based framework, the modified cooperative spectrum sensing framework can improve the Detection probability significantly, and the channel capacity can also be improved. Moreover, the amplification factor can be used to realize the tradeoff between Detection probability and channel capacity in our proposed framework.

关键词： cognitive radio cooperative spectrum sensing energy detection Detection probability channel capacity

Optimal Power Management for Antagonizing Between Radar and Jamming Based on Continuous Game Theory

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Transactions of Nanjing University of Aeronautics and Astronautics 2014年第4期31卷 386-393页

作者：万开方高晓光李波梅军峰 School of Electronics and Information Northwestern Polytechnical University

To solve the problem of dynamic power resource allocation for cooperative penetration combat,the continuous game theory is introduced and a two-person general-sum continuous-game-based model is put forward with a common payoff function named collaborative Detection probability of netted radar countermeasures.Comparing with traditional optimization methods,an obvious advantage of game-based model is an adequate consideration of the opposite potential strategy.This model guarantees a more effective allocation of the both sides′power resource and a higher combat efficiency during a combat.Furthermore,an analysis of the complexity of the proposed model is given and a hierarchical processing method is presented to simplify the calculating process.Simulation results show the validity of the proposed scheme.

关键词： game theory radar countermeasures power management Detection probability penetration combat

Detectability of the global weed Hypochaeris radicata is influenced by species, environment and observer characteristics

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Journal of Plant Ecology 2015年第4期8卷 449-455页

作者： Katherina Ng Don A.Driscoll ARC Centre of Excellence for Environmental Decisions The NERP Environmental Decisions HubFenner School of Environment and SocietyThe Australian National UniversityLinnaeus WayCanberraACT 2601Australia

Aims to determine the detectability of a global weedy perennial weed Hypochaeris radicata and its relationship with five common observer,species and environmental variables.Methods trained independent observers conducted time-limited repeat sur-veys of H.radicata during autumn in an endangered grassy box-gum woodland ecosystem in south-east australia.single-species single-season site-occupancy modelling was used to determine if detectability of H.radicata was altered by five covariates,observer,litter height,grazing,maximum plant height and flowering state.Important Findings Detectability for H.radicata varied significantly with observer,litter height,plant maximum height and flowering state,but not with graz-ing.Despite significant observer-specific variation,there was a con-sistent increase in detectability with plant height and when plants are in flower for all observers.Detectability generally decreased as litter height increases.Perfect or constant detection rates cannot be assumed in plant surveys,even for easily recognizable plants in simple survey conditions.understanding how detectability is influ-enced by common survey variables can help improve the efficacy of plant monitoring programs by quantifying the extent of uncertainty in inferences made from survey data,or by determining optimal sur-vey conditions to increase the reliability of collected data.For plants with traits similar to H.radicata,surveying when most plants are at maximum height or in flower,increasing search intensity when litter levels are high and minimizing observer-related heterogeneity are potentially simple and effective ways to reduce detection errors.We speculate that detection rates may be lower,more variable and involve additional covariates when surveying during the peak flow-ering spring season with the presence of more warm season and taller annual species.

关键词： Hypochaeris radicata grassy woodland Detection probability detectability vegetation survey plant monitoring observation bias false absence

Monitoring tigers with confidence

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Integrative Zoology 2010年第4期5卷 342-350页

作者： Matthew LINKIE Gurutzeta GUILLERA-ARROITA Joseph SMITH DMark RAYAN Fauna&Flora International CambridgeUK National Centre for Statistical Ecology School of MathematicsStatistics and Actuarial ScienceUniversity of KentCanterburyUK Panthera New YorkNYUSA WWF Malaysia SelangorMalaysia Durrell Institute of Conservation and Ecology University of KentCanterburyUK

With only 5%of the world’s wild tigers(Panthera tigris Linnaeus,1758)remaining since the last century,conservationists urgently need to know whether or not the management strategies currently being employed are effectively protecting these tigers.This knowledge is contingent on the ability to reliably monitor tiger populations,or subsets,over space and time.In the this paper,we focus on the 2 seminal methodologies(camera trap and occupancy surveys)that have enabled the monitoring of tiger populations with greater confidence.Specifically,we:(i)describe their statistical theory and application in the field;(ii)discuss issues associated with their survey designs and state variable modeling;and,(iii)discuss their future directions.These methods have had an unprecedented influence on increasing statistical rigor within tiger surveys and,also,surveys of other carnivore species.Nevertheless,only 2 published camera trap studies have gone beyond single baseline assessments and actually monitored population trends.For low density tiger populations(e.g.detection probabilities and/or sample sizes.Occupancy surveys have overcome this problem by redefining the sampling unit(e.***.grid cells and not individual tigers).Current research is focusing on developing spatially explicit capture-mark-recapture models and estimating abundance indices from landscape-scale occupancy surveys,as well as the use of genetic information for identifying and monitoring tigers.The widespread application of these monitoring methods in the field now enables complementary studies on the impact of the different threats to tiger populations and their response to varying management intervention.

关键词： capture carnivore Detection probability occupancy presence