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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.

detection probability Analysis of Space-Based AIS Signal by Using Geometrical Model

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Journal of Shipping and Ocean Engineering 2014年第5期4卷 161-171页

作者： Yuli Chen Merchant Marine College Shanghai Maritime University Shanghai 201306 China

To analyze the detection probability of shipbome AIS （automatic identification system） signal from space, a mathematical model dependent upon three factors of message collision avoidance, power of signal received by satellite and interference ratio of signal received is presented in the paper. The altitude and footprint area of the AIS satellite are discussed to overcome the collision of messages transmitted in the different time slots fxom different SOTDMA （self organizing time division multiple access） cell areas, but arrive at the same time slot due to the different signal path lengths. The simulated result shows that compared to the normal LEO （low ear~ orbit） satellite system, on average the maximum signal coverage area and the maximum FOV （field of view） of the AIS satellite system are reduced by 74% and 38%. The majority of power of signal transmitted fi＇om shipborne 12W-power AIS transmitters located within the maximum signal coverage area may be received with the sufficient margin of power of signal by the LEO satellite, but the space-based AIS system generally suffers from the insufficient CIR （carrier to co-channel interference ratio） of signal received since around 95% pairs of message simultaneously received by satellites may not be correctly decoded. The insufficient CIR of signal received is the bottleneck for the high message detection probability. Therefore, the measure of separating the collision messages should be further taken by the space-based AIS system to increase the detection probability.

关键词： A/S LEO satellite detection probability message collision distance delay signal margin CIR.

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 *** 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 *** the gate width is 100 ns,the ranging accuracy can accord with the requirements of satellite laser *** when the range gate width exceeds 400 ns,ranging accuracy will decline *** 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 *** 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 *** 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 ...

Study on the long-distance target apperception techniques for underwater vehicles

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 *** 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 *** 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 *** 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 *** 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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Journal of Systems Engineering and Electronics 2007年第3期18卷 484-490页

作者： Yang Xudong Huang Jianguo Zhang Qunfei Tang Qi Dept. of Electronics and Communication Engineering Coll. of Marine Engineering Northwestern Polytechnical Univ. Xi'an 710072 P. R. China

The limited physical size for autonomous underwater vehicles （AUV） or unmanned underwater vehicles （UUV） makes it difficult to acquire enough space gain for localizing long-distance targets. A new technique about long-distance target apperception with passive synthetic aperture array for underwater vehicles is presented. First, a synthetic aperture-processing algorithm based on the FFT transform in the beam space （BSSAP） is introduced. Then, the study on the flank array passive long-distance apperception techniques in the frequency scope of 11-18 kHz is implemented from the view of improving array gains, detection probability and augmenting detected range under a certain sea environment. The results show that the BSSAP algorithm can extend the aperture effectively and improve detection probability. Because of the augment of the transmission loss, the detected range has the trend of decline with the increase of frequency under the same target source level. The synthesized array could improve the space gain by nearly 7 dB and SNR is increased by about 5 dB. The detected range is enhanced to nearly 2 km under the condition of 108-118 dB of the target source level for AUV system in measurement interval of nearly 1 s.

关键词： long-distance apperception synthetic aperture processing array gain detection probability detectedrange.

Optimization of Multiband Spectrum Sensing for Cognitive Radio Networks under Sensing Capability Constrains

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China Communications 2010年第5期7卷 129-136页

作者： Zhao Chenglin Yao Haipeng Zhou Zheng Key Lab of Universal Wireless Communications Ministry of Education Wireless Network Lab Beijing University of Posts and Telecommunications Beijing 100876 P. R. China

This paper addresses the problem of joint optimization of subchannel selection and spectrum sensing time for multiband cognitive radio networks under the sensing capability constrains. In particular, we construct a multiband spectrum sensing framework, and derive the probabilities of detection and false alarm taking the different subchannel gain into account. Furthermore, we formulate the multi- band sensing as a two-parameter optimization prob- lem under the sensing capability constrains and guaranteeing the QoS of the secondary user. Moreover, we develop a semi-analytical optimization scheme to achieve the optimal solution.

关键词： multlbiand sensing cognitive radio detection probability false alarm 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

Design and observations of satellite laser ranging system for daylight tracking at Shanghai Observatory

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Science China Mathematics 1999年第2期42卷 198-206页

作者：杨福民肖炽昆陈婉珍张忠萍谭德同龚向东陈菊平黄力章建华 Shanghai Observatory Chinese Academy of Sciences Shanghai China

The first satellite laser ranging system for daylight tracking in China was set up at Shanghai Observatory, Chinese Academy of Sciences. Both false alarm probability due to strong background noises and detection probability of the laser returns with single photon level from satellite in daylight for our system are analysed. The system design and performance characteristics of subsystems, adopted techniques and satellite ranging observations are given.

关键词： satellite laser ranging aylight ranging 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