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Design of high-speed signal acquisition system and analysis of signal integrity 被引量:1
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作者 姚琴琴 谢锐 +1 位作者 白茹 申玉玲 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2015年第1期63-67,共5页
The device is used for the test on the fuze detonating time according to the initial velocity of the projectile and the altitude and speed of enemy aircraft flight. For the special requirements of the high-speed signa... The device is used for the test on the fuze detonating time according to the initial velocity of the projectile and the altitude and speed of enemy aircraft flight. For the special requirements of the high-speed signal acquisition in the process, the characteristics of the measured signal are analyzed. The system is investigated in chip selection, signal transmission, signal processing, signal storage, post-production PCB design, etc. The appropriate measures and solutions which affect the integrity and accuracy of the signal in each process are proposed. The rules for the layout of the device and wiring are made. The result show that the measurement values are accurate without loss of data. 展开更多
关键词 high-speed PCB simulation data acquisition signal integrity static storage
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Digital signal acquisition system for complex nuclear reaction experiments 被引量:1
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作者 Wei-Liang Pu Yan-Lin Ye +1 位作者 Jian-Ling Lou Jia-Hao Chen 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2024年第1期124-133,共10页
A digital data-acquisition system based on XIA LLC products was used in a complex nuclear reaction experiment using radioactive ion beams.A flexible trigger system based on a field-programmable gate array(FPGA)paramet... A digital data-acquisition system based on XIA LLC products was used in a complex nuclear reaction experiment using radioactive ion beams.A flexible trigger system based on a field-programmable gate array(FPGA)parametrization was developed to adapt to different experimental sizes.A user-friendly interface was implemented,which allows converting script language expressions into FPGA internal control parameters.The proposed digital system can be combined with a conventional analog data acquisition system to provide more flexibility.The performance of the combined system was veri-fied using experimental data. 展开更多
关键词 Digital signal acquisition system TRIGGER Programmable logic TIMESTAMP
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High-SpeedReal-TimeDataAcquisitionSystem Realized by Interleaving/Multiplexing Technique 被引量:1
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作者 吕洁 莫毅群 罗伟雄 《Journal of Beijing Institute of Technology》 EI CAS 2000年第2期183-188,共6页
The interleaving/multiplexing technique was used to realize a 200?MHz real time data acquisition system. Two 100?MHz ADC modules worked parallelly and every ADC plays out data in ping pang fashion. The design improv... The interleaving/multiplexing technique was used to realize a 200?MHz real time data acquisition system. Two 100?MHz ADC modules worked parallelly and every ADC plays out data in ping pang fashion. The design improved the system conversion rata to 200?MHz and reduced the speed of data transporting and storing to 50?MHz. The high speed HDPLD and ECL logic parts were used to control system timing and the memory address. The multi layer print board and the shield were used to decrease interference produced by the high speed circuit. The system timing was designed carefully. The interleaving/multiplexing technique could improve the system conversion rata greatly while reducing the speed of external digital interfaces greatly. The design resolved the difficulties in high speed system effectively. The experiment proved the data acquisition system is stable and accurate. 展开更多
关键词 real-time data acquisition interleaving/multiplexing high-speed AD converter
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Reflection on methodology of the correlation between electromagnetic interference and safety in high-speed railway
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作者 Chang Liu Shiwu Yang +2 位作者 Yixuan Yang Hefei Cao Shanghe Liu 《Railway Sciences》 2024年第1期84-96,共13页
Purpose – In the continuous development of high-speed railways, ensuring the safety of the operation controlsystem is crucial. Electromagnetic interference (EMI) faults in signaling equipment may cause transportation... Purpose – In the continuous development of high-speed railways, ensuring the safety of the operation controlsystem is crucial. Electromagnetic interference (EMI) faults in signaling equipment may cause transportationinterruptions, delays and even threaten the safety of train operations. Exploring the impact of disturbances onsignaling equipment and establishing evaluation methods for the correlation between EMI and safety isurgently needed.Design/methodology/approach – This paper elaborates on the necessity and significance of studying theimpact of EMI as an unavoidable and widespread risk factor in the external environment of high-speed railwayoperations and continuous development. The current status of research methods and achievements from theperspectives of standard systems, reliability analysis and safety assessment are examined layer by layer.Additionally, it provides prospects for innovative ideas for exploring the quantitative correlation between EMIand signaling safety.Findings – Despite certain innovative achievements in both domestic and international standard systems andrelated research for ensuring and evaluating railway signaling safety, there’s a lack of quantitative and strategic research on the degradation of safety performance in signaling equipment due to EMI. A quantitativecorrelation between EMI and safety has yet to be established. On this basis, this paper proposes considerationsfor research methods pertaining to the correlation between EMI and safety.Originality/value – This paper overviews a series of methods and outcomes derived from domestic andinternational studies regarding railway signaling safety, encompassing standard systems, reliability analysisand safety assessment. Recognizing the necessity for quantitatively describing and predicting the impact ofEMI on high-speed railway signaling safety, an innovative approach using risk assessment techniques as abridge to establish the correlation between EMI and signaling safety is proposed. 展开更多
关键词 Electromagnetic interference Reliability SAFETY Risk assessment signaling system high-speed railway
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A fine acquisition algorithm based on fast three-time FRFT for dynamic and weak GNSS signals 被引量:1
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作者 PAN YI ZHANG Sheng +2 位作者 WANG Xiao LIU Manhao LUO Yiran 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2023年第2期259-269,共11页
As high-dynamics and weak-signal are of two primary concerns of navigation using Global Navigation Satellite System(GNSS)signals,an acquisition algorithm based on threetime fractional Fourier transform(FRFT)is present... As high-dynamics and weak-signal are of two primary concerns of navigation using Global Navigation Satellite System(GNSS)signals,an acquisition algorithm based on threetime fractional Fourier transform(FRFT)is presented to simplify the calculation effectively.Firstly,the correlation results similar to linear frequency modulated(LFM)signals are derived on the basis of the high dynamic GNSS signal model.Then,the principle of obtaining the optimum rotation angle is analyzed,which is measured by FRFT projection lengths with two selected rotation angles.Finally,Doppler shift,Doppler rate,and code phase are accurately estimated in a real-time and low signal to noise ratio(SNR)wireless communication system.The theoretical analysis and simulation results show that the fast FRFT algorithm can accurately estimate the high dynamic parameters by converting the traditional two-dimensional search process to only three times FRFT.While the acquisition performance is basically the same,the computational complexity and running time are greatly reduced,which is more conductive to practical application. 展开更多
关键词 Global Navigation Satellite System(GNSS)signal fractional Fourier transform(FRFT) acquisition high-dynamics weak-signal
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High-speed broadband data acquisition system based on FPGA 被引量:2
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作者 刘军智 《Journal of Measurement Science and Instrumentation》 CAS 2013年第3期223-227,共5页
A field-programmable gate array(FPGA)based high-speed broadband data acquisition system is designed.The system has a dual channel simultaneous acquisition function.The maximum sampling rate is 500 MSa/s and bandwidth ... A field-programmable gate array(FPGA)based high-speed broadband data acquisition system is designed.The system has a dual channel simultaneous acquisition function.The maximum sampling rate is 500 MSa/s and bandwidth is200 MHz,which solves the large bandwidth,high-speed signal acquisition and processing problems.At present,the data acquisition system is successfully used in broadband receiver test systems. 展开更多
关键词 high-speed data acquisition FPGA WIDEBAND cross collection data combinationCLC number:TP274+.2 Document code:AArticle ID:1674-8042(2013)03-0223-05
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Reconstruction of sub cross-correlation cancellation technique for unambiguous acquisition of BOC(kn, n) signals 被引量:5
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作者 JI Yuanfa CHEN Xiaoqian +2 位作者 FU Qiang SUN Xiyan ZHEN Weimin 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2019年第5期852-860,共9页
In order to solve the problem of ambiguous acquisition of BOC signals caused by its property of multiple peaks,an unambiguous acquisition algorithm named reconstruction of sub cross-correlation cancellation technique(... In order to solve the problem of ambiguous acquisition of BOC signals caused by its property of multiple peaks,an unambiguous acquisition algorithm named reconstruction of sub cross-correlation cancellation technique(RSCCT)for BOC(kn,n)signals is proposed.In this paper,the principle of signal decomposition is combined with the traditional acquisition algorithm structure,and then based on the method of reconstructing the correlation function.The method firstly gets the sub-pseudorandom noise(PRN)code by decomposing the local PRN code,then uses BOC(kn,n)and the sub-PRN code cross-correlation to get the sub cross-correlation function.Finally,the correlation peak with a single peak is obtained by reconstructing the sub cross-correlation function so that the ambiguities of BOC acquisition are removed.The simulation shows that RSCCT can completely eliminate the side peaks of BOC(kn,n)group signals while maintaining the narrow correlation of BOC,and its computational complexity is equivalent to sub carrier phase cancellation(SCPC)and autocorrelation side-peak cancellation technique(ASPeCT),and it reduces the computational complexity relative to BPSK-like.For BOC(n,n),the acquisition sensitivity of RSCCT is 3.25 dB,0.81 dB and 0.25 dB higher than binary phase shift keying(BPSK)-like,SCPC and ASPeCT at the acquisition probability of 90%,respectively.The peak to average power ratio is 1.91,3.0 and 3.7 times higher than ASPeCT,SCPC and BPSK-like at SNR=–20 dB,respectively.For BOC(2n,n),the acquisition sensitivity of RSCCT is 5.5 dB,1.25 dB and 2.69 dB higher than BPSK-like,SCPC and ASPeCT at the acquisition probability of 90%,respectively.The peak to average power ratio is 1.02,1.68 and 2.12 times higher than ASPeCT,SCPC and BPSK-like at SNR=–20 dB,respectively. 展开更多
关键词 signal decomposition SUB CROSS-CORRELATION reconstructingcorrelation function acquisition performance
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Efficient and Innovative Techniques for Collective Acquisition of Weak GNSS Signals 被引量:5
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作者 Maherizo Andrianarison Mohamed Sahmoudi René Jr Landry 《Journal of Computer and Communications》 2017年第6期84-113,共30页
Navigation and positioning in harsh environments is still a great challenge for many applications. Collective Detection (CD) is a powerful approach for acquiring highly attenuated satellite signals in challenging envi... Navigation and positioning in harsh environments is still a great challenge for many applications. Collective Detection (CD) is a powerful approach for acquiring highly attenuated satellite signals in challenging environments, because of its capacity to process all visible satellites collectively taking advantage of the spatial correlation between GNSS signals as a vector acquisition scheme. CD combines the correlator outputs of satellite channels and projects them onto the position/clock bias domain in order to enhance the overall GNSS signal detection probability. In CD, the code phase search for all satellites in view is mapped into a receiver position/clock bias grid and the satellite signals are not acquired individually but collectively. In this concept, a priori knowledge of satellite ephemeris and reference location are provided to the user. Furthermore, CD addresses some of the inherent drawbacks of the conventional acquisition at the expenses of an increased computational cost. CD techniques are computationally intensive because of the significant number of candidate points in the position-time domain. The aim of this paper is to describe the operation of the CD approach incorporating new methods and architectures to address both the complexity and sensitivity problems. The first method consists of hybridizing the collective detection approach with some correlation techniques and coupling it with a better technique for Doppler frequency estimate. For that, a new scheme with less calculation load is proposed in order to accelerate the detection and location process. Then, high sensitivity acquisition techniques using long coherent integration and non-coherent integration are used in order to improve the performance of the CD algorithm. 展开更多
关键词 GNSS signalS acquisition WEAK signalS COLLECTIVE Detection Hybrid Scheme COLLABORATIVE acquisition
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Constant False Alarm Rate Acquisition Algorithm for Compass B1C Signal 被引量:1
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作者 Wengang Li Tianrong Qian +1 位作者 Yiwei Wang Chen Huang 《China Communications》 SCIE CSCD 2019年第11期201-211,共11页
In order to improve the sensitivity of the Compass B1C signal acquisition for the receiver,the principle of constant false alarm rate(CFAR)is applied for the B1C pilot channel acquisition to realize the dynamic adjust... In order to improve the sensitivity of the Compass B1C signal acquisition for the receiver,the principle of constant false alarm rate(CFAR)is applied for the B1C pilot channel acquisition to realize the dynamic adjustment of the threshold of acquisition against the carrier to noise ratio.The non-coherent data/pilot combined acquisition algorithm for B1C signal is analyzed to make full use of the power of the B1C signal under the condition of low carrier to noise ratio.On this basis,to improve the acquisition sensitivity of the receiver,the principle of constant false alarm probability is applied for the non-coherent data/pilot combined acquisition algorithm.Theoretical analysis and simulations show that the non-coherent data/pilot combined acquisition algorithm with CFAR improves the B1C signal acquisition sensitivity of the receiver significantly,and achieves a better Receiver Operating Characteristic compared with the traditional acquisition algorithms. 展开更多
关键词 B1C signal NON-COHERENT acquisition acquisition threshold constant false ALARM rate(CFAR)
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High Sensitivity Acquisition Algorithm for DSSS Signal with Data Modulation 被引量:3
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作者 SHEN Yuyao WANG Yongqing +1 位作者 CHEN Jingyao WU Siliang 《China Communications》 SCIE CSCD 2015年第4期76-85,共10页
In direct sequence spread spectrum communication both for satelliteto-ground and inter-satellite links, the system constrains due to radio frequency spectral occupation, channel data throughput and link performances i... In direct sequence spread spectrum communication both for satelliteto-ground and inter-satellite links, the system constrains due to radio frequency spectral occupation, channel data throughput and link performances in terms of data channel coding which might result in a signal structure where the symbol duration is shorter than the pseudo code period. This can generate some difficulties in the DSSS signal acquisition due to the polarity inversion caused by the data modulation. To eliminate the influence due to polarity inversion, this paper proposes a novel acquisition algorithm based on the simultaneous search of the code phase, data phase and Doppler frequency. In the proposed algorithm the data phase is predicted and the correlation period for the coherent integration can be set equal to the symbol duration. Then non-coherent accumulation over different symbol is implemented in order to enhance the acquisition algorithm sensitivity; the interval of non-coherent accumulation is the least common multiple between the symbol duration and the pseudo code period. The algorithm proposed can largely minimize the SNR loss caused by data polarity inversion and enhance acquisition performance without a noticeable increase in hardware complexity. Theoretical analysis, simulation and measured results verify the validity of the algorithm. 展开更多
关键词 DSSS signal acquisition dataphase prediction data polarity inversion segment search high sensitivity
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High-Sensitivity Acquisition of Ultrahigh Dynamic Direct Sequence Spread Spectrum Signals in Space Communications 被引量:2
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作者 徐颖 袁洪 《China Communications》 SCIE CSCD 2013年第10期26-36,共11页
According to the requirements of the high-sensitivity acquisition of Direct Sequence Spread Spectrum(DSSS) signals under ultrahigh dynamic environments in space communications, a three-dimensional joint search of the ... According to the requirements of the high-sensitivity acquisition of Direct Sequence Spread Spectrum(DSSS) signals under ultrahigh dynamic environments in space communications, a three-dimensional joint search of the phase of Pseudo-Noise-code(PN-code),Doppler frequency and its rate-of-change is presented to achieve high sensitivity in sensing high-frequency dynamics. By eliminating the correlation peak loss caused by ultrahigh Doppler frequency and its rate-of-change offset,the proposed method improves the acquisition sensitivity by increasing the non-coherent accumulation time. The validity of the algorithm is proved by theoretical analysis and simulation results. It is shown that signals with a carrier- to-noise ratio as low as 39 dBHz can be captured with high performance when the Doppler frequency is up to ±1 MHz and its rate-of-change is up to ±200 kHz/s. 展开更多
关键词 direct sequence spread spectrum signals space communications acquisition high sensitivity ultrahigh dynamic
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Impact of GPS Almanac Broadcast Strategy on the Signal Acquisition Time 被引量:1
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作者 Lu-Xiao Wang Zhi-Gang Huang Yun Zhao 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2013年第5期6-13,共8页
This paper investigates the problem of almanac affecting the signal acquisition time with two constraints: different age of data and multi-sets of almanac. The contributions made in this paper include: 1) the exploiti... This paper investigates the problem of almanac affecting the signal acquisition time with two constraints: different age of data and multi-sets of almanac. The contributions made in this paper include: 1) the exploiting of signal acquisition concept to extend well-known almanac function of predicting visible satellite and initializing signal acquisition to minimizing the signal acquisition time; 2) a model based on code phase and Doppler frequency to reflect the impact of multi-sets of almanac on the signal acquisition time; 3) the evaluation of the existing GPS almanac with different broadcast strategy. The theoretical analyses and simulations conducted on three sets of almanac show that the model proposed in this paper is general and efficient for almanac design and application. 展开更多
关键词 ALMANAC signal acquisition time age of data code phase doppler frequency
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Development of a wide-range and fast-response digitizing pulse signal acquisition and processing system for neutron flux monitoring on EAST 被引量:2
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作者 Li Yang Hong-Rui Cao +7 位作者 Jin-Long Zhao Zi-Han Zhang Qiang Li Guo-Bin Wu Yong-Qiang Zhang Guo-Qiang Zhong Li-Qun Hu Zi-Jun Zhang 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2022年第3期126-136,共11页
The neutron count rate fluctuation reaches six orders of magnitude between the ohmic plasma scenario and high power of auxiliary heating on an experimental advanced superconducting tokamak(EAST).The measurement result... The neutron count rate fluctuation reaches six orders of magnitude between the ohmic plasma scenario and high power of auxiliary heating on an experimental advanced superconducting tokamak(EAST).The measurement result of neutron flux monitoring(NFM)is a significant feedback parameter related to the acquisition of radiation protection-related information and rapid fluctuations in neutron emission induced by plasma magnetohydrodynamic activity.Therefore,a wide range and high time resolution are required for the NFM system on EAST.To satisfy these requirements,a digital pulse signal acquisition and processing system with a wide dynamic range and fast response time was developed.The present study was conducted using a field-programmable gate array(FPGA)and peripheral component interconnect extension for instrument express(PXIe)platform.The digital dual measurement modes,which are composed of the pulse-counting mode and AC coupled square integral's Campbelling mode,were designed to expand the measurement range of the signal acquisition and processing system.The time resolution of the signal acquisition and processing system was improved from 10 to 1 ms owing to utilizing highspeed analog-to-digital converters(ADCs),a high-speed PXIe communication with a direct memory access(DMA)mode,and online data preprocessing technology of FPGA.The signal acquisition and processing system was tested experimentally in the EAST radiation field.The test results showed that the time resolution of NFM was improved to 1 ms,and the dynamic range of the neutron counts rate was expanded to more than 10^(6) counts per second.The Campbelling mode was calibrated using a multipoint average linear fitting method;subsequently,the fitting coefficient reached 0.9911.Therefore,the newly developed pulse signal acquisition and processing system ensures that the NFM system meets the requirements of high-parameter experiments conducted on EAST more effectively. 展开更多
关键词 EAST Neutron flux monitoring High time resolution Wide range Pulse signal acquisition and processing system
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Re-scaling and adaptive stochastic resonance as a tool for weak GNSS signal acquisition 被引量:2
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作者 Rongling Lang Xinyue Li +1 位作者 Fei Gao Liang Yang 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2016年第2期290-296,共7页
Weak global navigation satellite system(GNSS) signal acquisition has been a limitation for high sensitivity GPS receivers. This paper modifies the traditional acquisition algorithms and proposes a new weak GNSS sign... Weak global navigation satellite system(GNSS) signal acquisition has been a limitation for high sensitivity GPS receivers. This paper modifies the traditional acquisition algorithms and proposes a new weak GNSS signal acquisition method using re-scaling and adaptive stochastic resonance(SR). The adoption of classical SR is limited to low-frequency and periodic signals. Given that GNSS signal frequency is high and that the periodic feature of the GNSS signal is affected by the Doppler frequency shift, classical SR methods cannot be directly used to acquire GNSS signals. Therefore, the re-scaling technique is used in our study to expand its usage to high-frequency signals and adaptive control technique is used to gradually determine the Doppler shift effect in GNSS signal buried in strong noises. The effectiveness of our proposed method was verified by the simulations on GPS L1 signals. The simulation results indicate that the new algorithm based on SR can reach-181 d BW sensitivity with a very short data length of 1 ms. 展开更多
关键词 weak signal detection global navigation satellite system(GNSS) signal acquisition stochastic resonance
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Two-step compressed acquisition method for Doppler frequency and Doppler rate estimation in high-dynamic and weak signal environments 被引量:1
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作者 WU Chao LIU Erxiao JIAN Zhihua 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2021年第4期831-840,共10页
To acquire global navigation satellite system(GNSS)signals means four-dimension acquisition of bit transition,Doppler frequency,Doppler rate,and code phase in high-dynamic and weak signal environments,which needs a hi... To acquire global navigation satellite system(GNSS)signals means four-dimension acquisition of bit transition,Doppler frequency,Doppler rate,and code phase in high-dynamic and weak signal environments,which needs a high computational cost.To reduce the computations,this paper proposes a twostep compressed acquisition method(TCAM)for the post-correlation signal parameters estimation.Compared with the fast Fourier transform(FFT)based methods,TCAM uses fewer frequency search points.In this way,the proposed method reduces complex multiplications,and uses real multiplications instead of improving the accuracy of the Doppler frequency and the Doppler rate.Furthermore,the differential process between two adjacent milliseconds is used for avoiding the impact of bit transition and the Doppler frequency on the integration peak.The results demonstrate that due to the reduction of complex multiplications,the computational cost of TCAM is lower than that of the FFT based method under the same signal to noise ratio(SNR). 展开更多
关键词 high-dynamic and weak signal environment compressed acquisition frequency parameters estimation
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Wing buzzing as a mechanism for generating vibrational signals in psyllids (Hemiptera: Psylloidea)
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作者 Jernej Polajnar Elizaveta Kvinikadze +1 位作者 Adam W.Harley Igor Malenovsky 《Insect Science》 SCIE CAS CSCD 2024年第5期1466-1476,共11页
Psyllids,or jumping plant lice(Hemiptera:Sternorrhyncha:Psylloidea),are a group of small phytophagous insects that include some important pests of crops world-wide.Sexual communication of psyllids occurs via vibration... Psyllids,or jumping plant lice(Hemiptera:Sternorrhyncha:Psylloidea),are a group of small phytophagous insects that include some important pests of crops world-wide.Sexual communication of psyllids occurs via vibrations transmitted through host plants,which play an important role in mate recognition and localization.The signals are species-specific and can be used to aid in psyllid taxonomy and pest control.Sev-eral hypotheses have been proposed for the mechanism that generates these vibrations,of which stridulation,that is,friction between parts of the forewing and thorax,has re-ceived the most attention.We have investigated vibrational communication in the Euro-pean pear psyllid species Cacopsylla pyrisuga(Foerster,1848)using laser vibrometry and high-speed video recording,to directly observe the movements associated with signal pro-duction.We describe for the first time the basic characteristics of the signals and signal emission of this species.Based on observations and analysis of the video recordings us-ing a point-tracking algorithm,and their comparison with laser vibrometer recordings,we argue that males of C.pyrisuga produce the vibrations primarily by wing buzzing,that is,tremulation that does not involve friction between the wings and thorax.Comparing observed signal properties with previously published data,we predict that wing buzzing is the main mechanism of signal production in all vibrating psyllids. 展开更多
关键词 Cacopsylla pyrisuga high-speed video recording jumping plant lice sexual communication substrate-borne vibrational signals vibrational communication
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An Improved Acquisition Algorithm for GPS Signals 被引量:1
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作者 Guoliang Zhu Xiaohui Chen 《通讯和计算机(中英文版)》 2010年第1期69-73,共5页
关键词 GPS信号 捕获算法 全球导航卫星系统 软件接收机 相关算法 种用 采集技术 频谱分析
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A new frequency domain search strategy in high sensitivity GPS signal acquisition circuit designing
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作者 邹德岳 孟维晓 +1 位作者 王文静 韩帅 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2012年第5期61-66,共6页
The contradiction between the sensitivity and the frequency domain searching speed of GPS signal acquisition circuit has been discussed for a long time. The signal integration operation which enhances the sensitivity ... The contradiction between the sensitivity and the frequency domain searching speed of GPS signal acquisition circuit has been discussed for a long time. The signal integration operation which enhances the sensitivity of the system also makes the frequency slots narrower, which affects the speed of the system. In this research a high sensitivity GPS signal acquisition circuit is implemented with a new frequency domain search strategy. The new strategy combines DDS sweep strategy with cyclic shifting sweep strategy which makes the TTFF (time to first fix) reduced evidently. The extra hardware resource cost of the new strategy is acceptable. The speed advantage of the new frequency domain search strategy has been verified by hardware comparison tests. 展开更多
关键词 GPS weak signal fast acquisition FPGA
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Fast Acquisition Method of GPS Signal Based on FFT Cyclic Correlation
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作者 Hao Cui Zhigang Li Zheng Dou 《International Journal of Communications, Network and System Sciences》 2017年第8期246-254,共9页
Since the global positioning system began to operate, it has become more and more close to people’s lives, and has been applied to various fields now. In order to track and decode GPS signals, GPS signals need to be ... Since the global positioning system began to operate, it has become more and more close to people’s lives, and has been applied to various fields now. In order to track and decode GPS signals, GPS signals need to be captured first. The necessary parameters of the captured GPS signal are immediately transmitted to the tracking process, and then the navigation message of the satellite can be obtained by tracking process. In this paper, the basic contents related to the signal structure of GPS system are briefly described. Then, the traditional GPS signal acquisition method based on time domain correlation method is introduced, and the GPS signal acquisition method based on FFT cyclic correlation method is discussed in this paper. By comparing the simulation results, two kinds of GPS signal acquisition methods are compared with the calculation time according to the method of controlling variables. For the two GPS signal acquisition methods, the variation of time delay error with SNR is simulated in this paper. 展开更多
关键词 GPS FFT SATELLITE signal acquisition CIRCULAR CORRELATION
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Acquisition of Weak Signals in Multi-Constellation Frequency Domain Receivers
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作者 Kaveh Mollaiyan Rock Santerre René Jr. Landry 《Positioning》 2013年第2期144-152,共9页
New positioning applications’ availability requirements demand receivers with higher sensitivities and ability to process multiple GNSS signals. Possible applications include acquiring one signal per GNSS constellati... New positioning applications’ availability requirements demand receivers with higher sensitivities and ability to process multiple GNSS signals. Possible applications include acquiring one signal per GNSS constellation in the same frequency band and combining them for increased sensitivity or predicting acquisition of other signals. Frequency domain processing can be used for this purpose, since it benefits from parallel processing capabilities of Fast Fourier Transform (FFT), which can be efficiently implemented in software receivers. On the other hand, long coherent integration times are mainly limited due to large FFT size in receivers using frequency domain techniques. A new method is proposed to address the problems in frequency domain receivers without compromising the resources and execution time. A pre-correlation accumulation (PCA) is proposed to partition the received samples into one-code-period blocks, and to sum them together. As a result, the noise is averaged out and the correlation results will gain more power, provided that the relative phase between the data segments is compensated for. In addition to simplicity, the proposed PCA method enables the use of one-size FFT for all integration times. A post-correlation peak combination is also proposed to remove the need for double buffering. The proposed methods are implemented in a configurable Simulink model, developed for acquiring recorded GNSS signals. For weak signal scenarios, a Spirent GPS simulator is used as a source. Acquisition results for GPS L1 C/A and GLONASS L1OF are shown and the performance of the proposed technique is discussed. The proposed techniques target GNSS receivers using frequency domain processing aiming at accommodating all the GNSS signals, while minimizing resource usage. They also apply to weak signal acquisition in frequency domain to answer the availability demand of today’s GNSS positioning applications. 展开更多
关键词 FFT acquisition Frequency Domain RECEIVER WEAK signal Multi-Constellation
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