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
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
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
Low Earth Orbit(LEO)satellite navigation signal can be used as an opportunity signal in the case of a Global Navigation Satellite System(GNSS)outage,or as an enhancement by means of traditional GNSS positioning algori...Low Earth Orbit(LEO)satellite navigation signal can be used as an opportunity signal in the case of a Global Navigation Satellite System(GNSS)outage,or as an enhancement by means of traditional GNSS positioning algorithms.No matter which service mode is used,signal acquisition is a prerequisite for providing enhanced LEO navigation services.Compared with the medium orbit satellite,the transit time of the LEO satellite is shorter.Thus,it is of great significance to expand the successful acquisition time range of the LEO signal.Previous studies on LEO signal acquisition are based on simulation data.However,signal acquisition research based on real data is crucial.In this work,the signal characteristics of LEO satellites:power space density in free space and the Doppler shift of LEO satellites are individually studied.The unified symbolic definitions of several integration algorithms based on the parallel search signal acquisition algorithm are given.To verify these algorithms for LEO signal acquisition,a Software Defined Receiver(SDR)is developed.The performance of these integration algorithms on expanding the successful acquisition time range is verified by the real data collected from the Luojia-1A satellite.The experimental results show that the integration strategy can expand the successful acquisition time range,and it will not expand indefinitely with the integration duration.The performance of the coherent integration and differential integration algorithms is better than the other two integration algorithms,so the two algorithms are recommended for LEO signal acquisition and a 20 ms integration duration is preferred.The detection threshold of 2.5 is not suitable for all integration algorithms and various integration durations,especially for the Maximum-to-Mean Ratio indicator.展开更多
We demonstrate a photonic architecture to enable the separation of ultra-wideband signals.The architecture consists of a channel-interleaved photonic analog-to-digital converter(PADC)and a dilated fully convolutional ...We demonstrate a photonic architecture to enable the separation of ultra-wideband signals.The architecture consists of a channel-interleaved photonic analog-to-digital converter(PADC)and a dilated fully convolutional network(DFCN).The aim of the PADC is to perform ultra-wideband signal acquisition,which introduces the mixing of signals between different frequency bands.To alleviate the interference among wideband signals,the DFCN is applied to reconstruct the waveform of the target signal from the ultra-wideband mixed signals in the time domain.The channel-interleaved PADC provides a wide spectrum reception capability.Relying on the DFCN reconstruction algorithm,the ultra-wideband signals,which are originally mixed up,are effectively separated.Additionally,experimental results show that the DFCN reconstruction algorithm improves the average bit error rate by nearly three orders of magnitude compared with that without the algorithm.展开更多
The conception of virtual separation technology about high low frequency of electronic module was put forward based on the analysis of tactical performance testing of radio fuse.By means of the principle of fuse Doppl...The conception of virtual separation technology about high low frequency of electronic module was put forward based on the analysis of tactical performance testing of radio fuse.By means of the principle of fuse Doppler signal acquisition and injection,the high low frequency of electronic module was virtually separated,and one of important parameters—burst height of radio fuse is tested precisely.展开更多
Technological advances in the semiconductor industry and the increasing demand and development of wearable medical systems have enabled the development of dedicated chips for complex electroencephalogram(EEG)signal pr...Technological advances in the semiconductor industry and the increasing demand and development of wearable medical systems have enabled the development of dedicated chips for complex electroencephalogram(EEG)signal processing with smart functions and artificial intelligence-based detections/classifications.Around 10 million transistors are integrated into a 1 mm2 silicon wafer surface in the dedicated chip,making wearable EEG systems a powerful dedicated processor instead of a wireless raw data transceiver.The reduction of amplifiers and analog-digital converters on the silicon surface makes it possible to place the analog front-end circuits within a tiny packaged chip;therefore,enabling high-count EEG acquisition channels.This article introduces and reviews the state-of-the-art dedicated chip designs for EEG processing,particularly for wearable systems.Furthermore,the analog circuits and digital platforms are included,and the technical details of circuit topology and logic architecture are presented in detail.展开更多
Purpose-With increasing demand of localization service in challenging environments where Global Navigation Satellite Systems(GNSS)signalsare considerably weak,a powerful approach,the collective detection(CD),has been ...Purpose-With increasing demand of localization service in challenging environments where Global Navigation Satellite Systems(GNSS)signalsare considerably weak,a powerful approach,the collective detection(CD),has been developed.However,traditional CD techniques are computationally intense due to the large clock bias search space.Therefore,the purpose of this paper is to develop a new scheme of CD with less computational burden,in order to accelerate the detection and location process.Design/methodology/approach-This paper proposes a new scheme of CD.It reformulates the problem ofGNSS signal detection as an optimization problem,and solves it with the aid of an improved Pigeon-Inspired Optimization(PIO).With the improved PIO algorithm adopted,the positioning algorithm arrives to evaluate only a part of the points in the search space,avoiding the problems of grid-search method which is universally adopted.Findings-Faced with the complex optimization problem,the improved PIO algorithm proves to have good performance.In the acquisition of simulated and real signals,the proposed scheme of CD with the improved PIO algorithm also have better efficiency,precision and stability than traditional CD algorithm.Besides,the improved PIO algorithm also proves to be a better candidate to be integrated into the proposed scheme than particle swarm optimization,differential evolution and PIO.Originality/value-The novelty associated with this paper is the proposition of the new scheme of CD and the improvement of PIO algorithm.Thus,this paper introduces another possibility to ameliorate the traditional CD.展开更多
基金This work was supported by the National Key R&D Program of China(Nos.2023YFA1606403 and 2023YFE0101600)the National Natural Science Foundation of China(Nos.12027809,11961141003,U1967201,11875073 and 11875074).
文摘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.
基金supported by the Users with Excellence Program of the Hefei Science Center CAS (No. 2020HSC-UE012)
文摘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.
基金Sponsored by the National Basic Research Program of China(Grant No.2010CB731800)the National Natural Science Foundation of China(GrantNo.60879012/F01)
文摘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.
基金the National Key R&D Program of China[grant number 2018YFB0505400]the Natural Science Fund of Hubei Province with Project[grant number 2018CFA007]National Key Research and Development Program of China[2018YFB0505400]。
文摘Low Earth Orbit(LEO)satellite navigation signal can be used as an opportunity signal in the case of a Global Navigation Satellite System(GNSS)outage,or as an enhancement by means of traditional GNSS positioning algorithms.No matter which service mode is used,signal acquisition is a prerequisite for providing enhanced LEO navigation services.Compared with the medium orbit satellite,the transit time of the LEO satellite is shorter.Thus,it is of great significance to expand the successful acquisition time range of the LEO signal.Previous studies on LEO signal acquisition are based on simulation data.However,signal acquisition research based on real data is crucial.In this work,the signal characteristics of LEO satellites:power space density in free space and the Doppler shift of LEO satellites are individually studied.The unified symbolic definitions of several integration algorithms based on the parallel search signal acquisition algorithm are given.To verify these algorithms for LEO signal acquisition,a Software Defined Receiver(SDR)is developed.The performance of these integration algorithms on expanding the successful acquisition time range is verified by the real data collected from the Luojia-1A satellite.The experimental results show that the integration strategy can expand the successful acquisition time range,and it will not expand indefinitely with the integration duration.The performance of the coherent integration and differential integration algorithms is better than the other two integration algorithms,so the two algorithms are recommended for LEO signal acquisition and a 20 ms integration duration is preferred.The detection threshold of 2.5 is not suitable for all integration algorithms and various integration durations,especially for the Maximum-to-Mean Ratio indicator.
基金the National Key R&D Program of China(No.2019YFB2203700)the National Natu ral Science Foundation of China(Nos.61822508 and 61571292).
文摘We demonstrate a photonic architecture to enable the separation of ultra-wideband signals.The architecture consists of a channel-interleaved photonic analog-to-digital converter(PADC)and a dilated fully convolutional network(DFCN).The aim of the PADC is to perform ultra-wideband signal acquisition,which introduces the mixing of signals between different frequency bands.To alleviate the interference among wideband signals,the DFCN is applied to reconstruct the waveform of the target signal from the ultra-wideband mixed signals in the time domain.The channel-interleaved PADC provides a wide spectrum reception capability.Relying on the DFCN reconstruction algorithm,the ultra-wideband signals,which are originally mixed up,are effectively separated.Additionally,experimental results show that the DFCN reconstruction algorithm improves the average bit error rate by nearly three orders of magnitude compared with that without the algorithm.
文摘The conception of virtual separation technology about high low frequency of electronic module was put forward based on the analysis of tactical performance testing of radio fuse.By means of the principle of fuse Doppler signal acquisition and injection,the high low frequency of electronic module was virtually separated,and one of important parameters—burst height of radio fuse is tested precisely.
基金supported by the National Natural Science Foundation of China(Grant No.61974095)the Natural Science Foundation of Guangdong Province,China(Grant No.2018A030313169)+1 种基金the Foundation for Young Talents in Higher Education of Guangdong(Grant No.2018KQNCX405)the Natural Science Foundation of Top Talent of SZTU(Grant No.2019010801004)
文摘Technological advances in the semiconductor industry and the increasing demand and development of wearable medical systems have enabled the development of dedicated chips for complex electroencephalogram(EEG)signal processing with smart functions and artificial intelligence-based detections/classifications.Around 10 million transistors are integrated into a 1 mm2 silicon wafer surface in the dedicated chip,making wearable EEG systems a powerful dedicated processor instead of a wireless raw data transceiver.The reduction of amplifiers and analog-digital converters on the silicon surface makes it possible to place the analog front-end circuits within a tiny packaged chip;therefore,enabling high-count EEG acquisition channels.This article introduces and reviews the state-of-the-art dedicated chip designs for EEG processing,particularly for wearable systems.Furthermore,the analog circuits and digital platforms are included,and the technical details of circuit topology and logic architecture are presented in detail.
文摘Purpose-With increasing demand of localization service in challenging environments where Global Navigation Satellite Systems(GNSS)signalsare considerably weak,a powerful approach,the collective detection(CD),has been developed.However,traditional CD techniques are computationally intense due to the large clock bias search space.Therefore,the purpose of this paper is to develop a new scheme of CD with less computational burden,in order to accelerate the detection and location process.Design/methodology/approach-This paper proposes a new scheme of CD.It reformulates the problem ofGNSS signal detection as an optimization problem,and solves it with the aid of an improved Pigeon-Inspired Optimization(PIO).With the improved PIO algorithm adopted,the positioning algorithm arrives to evaluate only a part of the points in the search space,avoiding the problems of grid-search method which is universally adopted.Findings-Faced with the complex optimization problem,the improved PIO algorithm proves to have good performance.In the acquisition of simulated and real signals,the proposed scheme of CD with the improved PIO algorithm also have better efficiency,precision and stability than traditional CD algorithm.Besides,the improved PIO algorithm also proves to be a better candidate to be integrated into the proposed scheme than particle swarm optimization,differential evolution and PIO.Originality/value-The novelty associated with this paper is the proposition of the new scheme of CD and the improvement of PIO algorithm.Thus,this paper introduces another possibility to ameliorate the traditional CD.
