Traditional digitizers for signal readout of PET detectors are based on commercial analog-to-digital converters(ADC).However,the cost and power consumption of an entire electronic readout system based on digitizers fo...Traditional digitizers for signal readout of PET detectors are based on commercial analog-to-digital converters(ADC).However,the cost and power consumption of an entire electronic readout system based on digitizers for a PET scanner are high.To address this problem,a soft-core ADC based on a field-programmable gate array(FPGA)was proposed.An FPGA-based ADC(FPGA-ADC)combines low loss and high performance.To achieve good performance,the FPGA-ADC requires three calibrations:time-to-digital converter(TDC)length calibration,TDC alignment calibration,and TDC-to-ADC calibration.A prototype front-end electronics based on FPGA-ADC was built to evaluate the performance of time-of-flight positron emission tomography(TOF PET)detectors.Each PET detector consists of a LYSO crystal single-ended coupled to a silicon photomultiplier(SiPM).The experimental results show that the full-width at half-maximum(FWHM)energy resolution for 511 keV gamma photons after saturation correction of the SiPM was 12.3%.The FWHM coincidence timing resolution(CTR)of the TOF PET detector with the readout of the front-end electronic prototype is 385.2 ps.FPGA-ADCbased front-end electronics are very promising for multichannel,low-cost,highly integrated,and power-efficient readout electronic systems for radiation detector applications.展开更多
随着卫星通信技术的迅速发展,卫星互联网已成为现代通信的重要组成部分。机载卫星通信终端及其核心组件的性能直接决定了通信系统的效率与可靠性。目前,这些关键组件的研发主要由国外企业垄断,限制了技术的发展并且成本高昂。通过对比5G...随着卫星通信技术的迅速发展,卫星互联网已成为现代通信的重要组成部分。机载卫星通信终端及其核心组件的性能直接决定了通信系统的效率与可靠性。目前,这些关键组件的研发主要由国外企业垄断,限制了技术的发展并且成本高昂。通过对比5G NR NTN和DVB-S2X/RCS2两种主流卫星通信体制,总结出卫通终端的功能性能指标,并结合机载环境下的需求,分析了典型卫通终端协议模块的架构和指标。最后,研究总结了基于5G NR和DVB标准的测试指标及方法,以提高测试效能,并实现产品的实时自检应用。展开更多
安全播出是广播电视的生命线。作为有线电视运营和管理部门,数字电视前端系统的安全性和稳定性对确保数字视频广播(Digital Video Broadcasting,DVB)安全播出至关重要。基于市级下传的4路不同路由的源信号,并依托两处机房条件,构建了主...安全播出是广播电视的生命线。作为有线电视运营和管理部门,数字电视前端系统的安全性和稳定性对确保数字视频广播(Digital Video Broadcasting,DVB)安全播出至关重要。基于市级下传的4路不同路由的源信号,并依托两处机房条件,构建了主备DVB前端系统。鉴于原系统存在的安全隐患,提出嘉善华数DVB前端平台的改造方案。经过6个月的建设和运行近,该系统展现出高度的安全性和可靠性、运行平稳,成功实现了设计目标。展开更多
详细探讨基于第二代地面数字视频广播(Digital Video Broadcasting-Terrestrial 2,DVB-T2)标准的数字广播信号抗干扰技术,包括多天线技术(Multiple-Input Multiple-Output,MIMO)在抗干扰中的应用、干扰识别与抑制算法的开发、信号纠错...详细探讨基于第二代地面数字视频广播(Digital Video Broadcasting-Terrestrial 2,DVB-T2)标准的数字广播信号抗干扰技术,包括多天线技术(Multiple-Input Multiple-Output,MIMO)在抗干扰中的应用、干扰识别与抑制算法的开发、信号纠错与恢复机制的优化及卷积编码与交织技术的改进。通过理论分析与技术应用测试,显示这些创新措施可显著提高广播信号的稳定性和抗干扰能力,为数字广播系统在多变环境下的可靠运行提供有效支持。展开更多
Traditionally,a continuous-wave(CW)signal is used to simulate RF circuits during the design procedure,while the fabricated circuits are measured by modulated signals in the test phase,because modulated signals are use...Traditionally,a continuous-wave(CW)signal is used to simulate RF circuits during the design procedure,while the fabricated circuits are measured by modulated signals in the test phase,because modulated signals are used in reality.It is almost impossible to use a CW signal to predict system performances,such as error vector magnitude(EVM),bit error rate(BER),etc.,of a transceiver front-end when dealing with complex modulated signals.This paper develops an integrated system evaluation engine(ISEE)to evaluate the system performances of a transceiver front-end or its sub-circuits.This crossdomain simulation platform is based on Matlab,advanced design system(ADS),and Cadence simulators to link the baseband signals and transceiver frond-end.An orthogonal frequency division multiplex(OFDM)modem is implemented in Matlab for evaluating the system performances.The modulated baseband signal from Matlab is dynamically fed into ADS,which includes transceiver front-end for co-simulation.The sub-block circuits of the transceiver front-end can be implemented using ADS and Cadence simulators.After system-level circuit simulation in ADS,the output signal is dynamically delivered to Matlab for demodulation.To simplify the use of the co-simulation platform,a graphical user interface(GUI)is constructed using Matlab.The parameters of the OFDM signals can be easily reconfigured on the GUI to simulate RF circuits with different modulation schemes.To demonstrate the effectiveness of the ISEE,a 3.5 GHz power amplifier is simulated and characterized using 20 MHz 16-and 64-QAM OFDM signals.展开更多
In response to the pain points of rapid iteration of front-end education technology,large differences in learner foundations,and a lack of practical scenarios,this paper combines generative artificial intelligence and...In response to the pain points of rapid iteration of front-end education technology,large differences in learner foundations,and a lack of practical scenarios,this paper combines generative artificial intelligence and AI agents to analyze the empowerment logic from three dimensions:knowledge ecology reconstruction,cognitive collaborative upgrading,and teaching methodology innovation.It explores its application scenarios in teaching and learning,sorts out challenges such as technology adaptation and learning dependence,and proposes paths such as building an exclusive AI ecosystem and optimizing the guidance mechanism of intelligent agents to provide support for the digital transformation of front-end education.展开更多
随着数字电视的普及与发展,采用基于第二代地面数字视频广播(Digital Video Broadcasting-Terrestrial Second Generation,DVB-T2)技术的电视信号转播方案已经成为提升广播信号质量和覆盖范围的关键。针对电视信号塔的实时转播方案进行...随着数字电视的普及与发展,采用基于第二代地面数字视频广播(Digital Video Broadcasting-Terrestrial Second Generation,DVB-T2)技术的电视信号转播方案已经成为提升广播信号质量和覆盖范围的关键。针对电视信号塔的实时转播方案进行系统设计,重点分析不同环境下信号转播的技术需求。通过分析DVB-T2信号塔的系统架构、信号处理、传输链路、天线布局及频率分配等设计要点,提出一种具有高效性和实用性的实时转播方案,并保证方案在城市、山区和郊区等不同环境下的适配性,以实现广泛且稳定的信号覆盖。展开更多
地面数字电视广播(Digital Video Broadcasting-Terrestrial,DVB-T)技术凭借其高频谱利用率、抗干扰性及高速移动适应性,为地铁车地无线通信系统提供高效解决方案。文章分析DVB-T的应用优势,探讨其在乘客信息发布与多媒体广播服务、列...地面数字电视广播(Digital Video Broadcasting-Terrestrial,DVB-T)技术凭借其高频谱利用率、抗干扰性及高速移动适应性,为地铁车地无线通信系统提供高效解决方案。文章分析DVB-T的应用优势,探讨其在乘客信息发布与多媒体广播服务、列车监控与运营数据回传、应急通信与安全信息发布等领域的应用路径,并针对复杂环境下的信道干扰、频谱效率提升及低时延传输等关键问题提出优化措施。展开更多
为提高地面数字电视广播(DVB-T)接收机的实现灵活性,基于由通用软件无线电外设(Universal Software Radio Peripheral,USRP)和通用计算机组成的软件无线电平台,实现DVB-T接收机。接收机以USRP作为射频前端,在通用计算机中完成全部基带...为提高地面数字电视广播(DVB-T)接收机的实现灵活性,基于由通用软件无线电外设(Universal Software Radio Peripheral,USRP)和通用计算机组成的软件无线电平台,实现DVB-T接收机。接收机以USRP作为射频前端,在通用计算机中完成全部基带信号处理、视频解码与显示等。测试结果表明,接收机可实现对DVB-T信号的接收,为接收机算法开发、验证与评估提供了更为灵活的方法。展开更多
构建IPv6 over DVB体系框架,可以在下一代互联网中利用卫星等广播信道实施远程教育。该体系框架包括"支持IPv6的教育资源管理与发布系统"、"IPv6 over DVB传输系统"以及"IPv6 over DVB在远程教育中的应用示范&...构建IPv6 over DVB体系框架,可以在下一代互联网中利用卫星等广播信道实施远程教育。该体系框架包括"支持IPv6的教育资源管理与发布系统"、"IPv6 over DVB传输系统"以及"IPv6 over DVB在远程教育中的应用示范"3个部分。实现了将IPv6互联网中的教育资源通过卫星链路发布到目前尚无网络覆盖的1000所农牧村中小学。给出了设计方案和部署策略。展开更多
基金supported by the Key R&D Program of Shandong Province(No.2023SFGC0101)Shandong Excellent Young Scientists Fund Program(Overseas)(No.2023HWYQ-047)+1 种基金the Natural Science Foundation of Shandong Province(No.ZR2022QA039)the National Natural Science Foundation of China(NSFC)(No.U2106202).
文摘Traditional digitizers for signal readout of PET detectors are based on commercial analog-to-digital converters(ADC).However,the cost and power consumption of an entire electronic readout system based on digitizers for a PET scanner are high.To address this problem,a soft-core ADC based on a field-programmable gate array(FPGA)was proposed.An FPGA-based ADC(FPGA-ADC)combines low loss and high performance.To achieve good performance,the FPGA-ADC requires three calibrations:time-to-digital converter(TDC)length calibration,TDC alignment calibration,and TDC-to-ADC calibration.A prototype front-end electronics based on FPGA-ADC was built to evaluate the performance of time-of-flight positron emission tomography(TOF PET)detectors.Each PET detector consists of a LYSO crystal single-ended coupled to a silicon photomultiplier(SiPM).The experimental results show that the full-width at half-maximum(FWHM)energy resolution for 511 keV gamma photons after saturation correction of the SiPM was 12.3%.The FWHM coincidence timing resolution(CTR)of the TOF PET detector with the readout of the front-end electronic prototype is 385.2 ps.FPGA-ADCbased front-end electronics are very promising for multichannel,low-cost,highly integrated,and power-efficient readout electronic systems for radiation detector applications.
文摘随着卫星通信技术的迅速发展,卫星互联网已成为现代通信的重要组成部分。机载卫星通信终端及其核心组件的性能直接决定了通信系统的效率与可靠性。目前,这些关键组件的研发主要由国外企业垄断,限制了技术的发展并且成本高昂。通过对比5G NR NTN和DVB-S2X/RCS2两种主流卫星通信体制,总结出卫通终端的功能性能指标,并结合机载环境下的需求,分析了典型卫通终端协议模块的架构和指标。最后,研究总结了基于5G NR和DVB标准的测试指标及方法,以提高测试效能,并实现产品的实时自检应用。
文摘安全播出是广播电视的生命线。作为有线电视运营和管理部门,数字电视前端系统的安全性和稳定性对确保数字视频广播(Digital Video Broadcasting,DVB)安全播出至关重要。基于市级下传的4路不同路由的源信号,并依托两处机房条件,构建了主备DVB前端系统。鉴于原系统存在的安全隐患,提出嘉善华数DVB前端平台的改造方案。经过6个月的建设和运行近,该系统展现出高度的安全性和可靠性、运行平稳,成功实现了设计目标。
文摘详细探讨基于第二代地面数字视频广播(Digital Video Broadcasting-Terrestrial 2,DVB-T2)标准的数字广播信号抗干扰技术,包括多天线技术(Multiple-Input Multiple-Output,MIMO)在抗干扰中的应用、干扰识别与抑制算法的开发、信号纠错与恢复机制的优化及卷积编码与交织技术的改进。通过理论分析与技术应用测试,显示这些创新措施可显著提高广播信号的稳定性和抗干扰能力,为数字广播系统在多变环境下的可靠运行提供有效支持。
基金supported by the Project of Hetao Shenzhen-Hong Kong Science and Technology Innovation Cooperation Zone(No.HZQB-KCZYB-2020083).
文摘Traditionally,a continuous-wave(CW)signal is used to simulate RF circuits during the design procedure,while the fabricated circuits are measured by modulated signals in the test phase,because modulated signals are used in reality.It is almost impossible to use a CW signal to predict system performances,such as error vector magnitude(EVM),bit error rate(BER),etc.,of a transceiver front-end when dealing with complex modulated signals.This paper develops an integrated system evaluation engine(ISEE)to evaluate the system performances of a transceiver front-end or its sub-circuits.This crossdomain simulation platform is based on Matlab,advanced design system(ADS),and Cadence simulators to link the baseband signals and transceiver frond-end.An orthogonal frequency division multiplex(OFDM)modem is implemented in Matlab for evaluating the system performances.The modulated baseband signal from Matlab is dynamically fed into ADS,which includes transceiver front-end for co-simulation.The sub-block circuits of the transceiver front-end can be implemented using ADS and Cadence simulators.After system-level circuit simulation in ADS,the output signal is dynamically delivered to Matlab for demodulation.To simplify the use of the co-simulation platform,a graphical user interface(GUI)is constructed using Matlab.The parameters of the OFDM signals can be easily reconfigured on the GUI to simulate RF circuits with different modulation schemes.To demonstrate the effectiveness of the ISEE,a 3.5 GHz power amplifier is simulated and characterized using 20 MHz 16-and 64-QAM OFDM signals.
基金funded by two 2024 Ministry of Education supply-demand docking employment and education projects(Grant No.2024101679202,Grant No.2024121116066)2024“Innovation Strong Institute Project of Guangdong Polytechnic Institute”(Grant No.2024CQ-29)2022 Guangdong Province Undergraduate Online Open Course Guidance Committee Research Project(Grant No.2022ZXKC612).
文摘In response to the pain points of rapid iteration of front-end education technology,large differences in learner foundations,and a lack of practical scenarios,this paper combines generative artificial intelligence and AI agents to analyze the empowerment logic from three dimensions:knowledge ecology reconstruction,cognitive collaborative upgrading,and teaching methodology innovation.It explores its application scenarios in teaching and learning,sorts out challenges such as technology adaptation and learning dependence,and proposes paths such as building an exclusive AI ecosystem and optimizing the guidance mechanism of intelligent agents to provide support for the digital transformation of front-end education.
文摘随着数字电视的普及与发展,采用基于第二代地面数字视频广播(Digital Video Broadcasting-Terrestrial Second Generation,DVB-T2)技术的电视信号转播方案已经成为提升广播信号质量和覆盖范围的关键。针对电视信号塔的实时转播方案进行系统设计,重点分析不同环境下信号转播的技术需求。通过分析DVB-T2信号塔的系统架构、信号处理、传输链路、天线布局及频率分配等设计要点,提出一种具有高效性和实用性的实时转播方案,并保证方案在城市、山区和郊区等不同环境下的适配性,以实现广泛且稳定的信号覆盖。
文摘地面数字电视广播(Digital Video Broadcasting-Terrestrial,DVB-T)技术凭借其高频谱利用率、抗干扰性及高速移动适应性,为地铁车地无线通信系统提供高效解决方案。文章分析DVB-T的应用优势,探讨其在乘客信息发布与多媒体广播服务、列车监控与运营数据回传、应急通信与安全信息发布等领域的应用路径,并针对复杂环境下的信道干扰、频谱效率提升及低时延传输等关键问题提出优化措施。
文摘为提高地面数字电视广播(DVB-T)接收机的实现灵活性,基于由通用软件无线电外设(Universal Software Radio Peripheral,USRP)和通用计算机组成的软件无线电平台,实现DVB-T接收机。接收机以USRP作为射频前端,在通用计算机中完成全部基带信号处理、视频解码与显示等。测试结果表明,接收机可实现对DVB-T信号的接收,为接收机算法开发、验证与评估提供了更为灵活的方法。
文摘构建IPv6 over DVB体系框架,可以在下一代互联网中利用卫星等广播信道实施远程教育。该体系框架包括"支持IPv6的教育资源管理与发布系统"、"IPv6 over DVB传输系统"以及"IPv6 over DVB在远程教育中的应用示范"3个部分。实现了将IPv6互联网中的教育资源通过卫星链路发布到目前尚无网络覆盖的1000所农牧村中小学。给出了设计方案和部署策略。
