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Evaluation of second-order Zeeman frequency shift in NTSC-F2 被引量:1
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作者 Jun-Ru Shi Xin-Liang Wang +5 位作者 Yang Bai Fan Yang Yong Guan Dan-Dan Liu Jun Ruan Shou-Gang Zhang 《Chinese Physics B》 SCIE EI CAS CSCD 2021年第7期163-170,共8页
Caesium atomic fountain clock is a primary frequency standard,which realizes the duration of second.Its performance is mostly dominated by the frequency accuracy,and the C-field induced second-order Zeeman frequency s... Caesium atomic fountain clock is a primary frequency standard,which realizes the duration of second.Its performance is mostly dominated by the frequency accuracy,and the C-field induced second-order Zeeman frequency shift is the major effect,which limits the accuracy improvement.By applying a high-precision current supply and high-performance magnetic shieldings,the C-field stability has been improved significantly.In order to achieve a uniform C-field,this paper proposes a doubly wound C-field solenoid,which compensates the radial magnetic field along the atomic flight region generated by the lead-out single wire and improves the accuracy evaluation of second-order Zeeman frequency shift.Based on the stable and uniform C-field,we launch the selected atoms to different heights and record the magnetically sensitive Ramsey transition|F=3,mF=-1→|F=4,mF=-1 central frequency,obtaining this frequency shift as 131.03×10^(-15)and constructing the C-field profile(σ=0.15 n T).Meanwhile,during normal operation,we lock NTSC-F2 to the central frequency of the magnetically sensitive Ramsey transition|F=3,mF=-1→|F=4,mF=-1 fringe for ten consecutive days and record this frequency fluctuation in time domain.The first evaluation of second-order Zeeman frequency shift uncertainty is 0.10×10^(-15).The total deviation of the frequency fluctuation on the clock transition induced by the C-field instability is less than 2.6×10^(-17).Compared with NTSC-F1,NTSC-F2,there appears a significant improvement. 展开更多
关键词 caesium atomic fountain clock second-order Zeeman frequency shift C-field magnetic shielding
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Adaptive compensating method for Doppler frequency shift using LMS and phase estimation 被引量:7
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作者 Jing Qingfeng Guo Qing 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2009年第5期913-919,共7页
The novel compensating method directly demodulates the signals without the carrier recovery processes, in which the carrier with original modulation frequency is used as the local coherent carrier. In this way, the ph... The novel compensating method directly demodulates the signals without the carrier recovery processes, in which the carrier with original modulation frequency is used as the local coherent carrier. In this way, the phase offsets due to frequency shift are linear. Based on this premise, the compensation processes are: firstly, the phase offsets between the baseband neighbor-symbols after clock recovery is unbiasedly estimated among the reference symbols; then, the receiving signals symbols are adjusted by the phase estimation value; finally, the phase offsets after adjusting are compensated by the least mean squares (LMS) algorithm. In order to express the compensation processes and ability clearly, the quadrature phase shift keying (QPSK) modulation signals are regarded as examples for Matlab simulation. BER simulations are carried out using the Monte-Carlo method. The learning curves are obtained to study the algorithm's convergence ability. The constellation figures are also simulated to observe the compensation results directly. 展开更多
关键词 doppler frequency shift least mean square minimum phase shift keying unbiased estimation Matlab simulation.
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Thin-film lithium niobate dual-parallel Mach-Zehnder modulator for a simple photonic system measuring Doppler frequency shift 被引量:1
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作者 Jinming Tao Xintong Li +4 位作者 Run Li Peng Wang Tian Zhang Jinye Li Jianguo Liu 《Chinese Optics Letters》 SCIE EI CAS CSCD 2024年第9期19-25,共7页
In recent years,thin-film lithium niobate(TFLN)electro-optic(EO)modulators have developed rapidly and are the core solution for the next generation of microwave photonics(MWP)problems.We designed and fabricated a dual... In recent years,thin-film lithium niobate(TFLN)electro-optic(EO)modulators have developed rapidly and are the core solution for the next generation of microwave photonics(MWP)problems.We designed and fabricated a dual-parallel Mach-Zehnder modulator(DPMZM)based on TFLN,achieving a 3 dB electro-electro(EE)bandwidth of 29 GHz and a low drive voltage(Vπ=6 V).The device we manufactured is metal-encapsulated.It is noteworthy that we proposed a single-channel Doppler frequency shift(DFS)measurement system based on this device and conducted verification experiments.We coupled light from an external laser into the chip and passed it through each of the two sub-MZMs of the DPMZM.These lights were modulated by echo signals and reference signals.By measuring the frequency of the output signal,we can obtain a DFS value without directional ambiguity.The success of this experiment marks a key step in the practical application of TFLN modulators in MWP. 展开更多
关键词 dual-parallel Mach-Zehnder modulator lithium niobate on insulator doppler frequency shift microwave photonics.
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Effect Due to the Particle Nature of the Doppler Shifted Radiation on the Dynamics of the Spherical Light Emitting Source
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作者 Sameer Yadav 《Journal of High Energy Physics, Gravitation and Cosmology》 2023年第3期693-698,共6页
The Doppler effect is a phenomenon of intrinsic kinematic character. This paper analyzes the kinematic Doppler effect for the case where the source is moving and the observer is at rest in the classical limit. The par... The Doppler effect is a phenomenon of intrinsic kinematic character. This paper analyzes the kinematic Doppler effect for the case where the source is moving and the observer is at rest in the classical limit. The particle nature properties of radiation are considered and how it affects the dynamics of the Source has been studied. The dynamical and kinematical equations have been derived by considering this effect. It has been conclusively shown that a moving light-emitting source experiences a finite recoil momentum in the direction opposite to the direction of motion and come to rest in finite time. 展开更多
关键词 doppler Effect Light Emission frequency shift Recoil Momentum
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Analysis of the influence of various effects on frequency shifts of the acetylene saturated absorption lines 被引量:1
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作者 董磊 张雷 +2 位作者 窦海鹏 尹王保 贾锁堂 《Chinese Physics B》 SCIE EI CAS CSCD 2008年第1期152-157,共6页
Frequency shifts of the acetylene saturated absorption lines at 1.5μm with temperature, gas pressure and laser power have been investigated in detail. The second-order Doppler effect, the recoil effect, the Zeeman ef... Frequency shifts of the acetylene saturated absorption lines at 1.5μm with temperature, gas pressure and laser power have been investigated in detail. The second-order Doppler effect, the recoil effect, the Zeeman effect, the pressure shift and the power shift are taken into consideration. The magnitudes of those shifts caused by various effects are evaluated. In order to reproduce the stability of 5.7 × 10^-14 obtained by Edwards, all necessary conditions are given. The results show that when there is a larger external magnetic field, the Zeeman shift could not be neglected, so that the shield should be employed. And the design of a long cavity is advantageous to reduce the influence of the second-order Doppler effect. The results also show that at least 4-2.5℃ temperature control for cavity can effectively prevent several effects and improve the frequency stability. 展开更多
关键词 frequency shifts sub-doppler spectroscopy ACETYLENE cavity-enhanced absorption technique
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PULSE CUMULATING METHOD FOR MULTI-TARGETS' JOINT AZIMUTH-ELEVATION FREQUENCY-DELAY ESTIMATION
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作者 Wu Xianglin Yu Bianzhang +1 位作者 Xie Hongmei Song Zuxun 《Journal of Electronics(China)》 2006年第3期370-373,共4页
The Directions of Arrivals (DOAs), speeds and distances of targets are all required for array signal processing. Based on the periodic phase shift of coherent pulse sequence waveform, a new estimation of multi-targ... The Directions of Arrivals (DOAs), speeds and distances of targets are all required for array signal processing. Based on the periodic phase shift of coherent pulse sequence waveform, a new estimation of multi-targets' 2-Dimentional (2-D) DOA angle, Doppler frequency shift and relative time-delay is proposed. Based on a virtual sensor array constructed by pulse cumulating, the estinaations of azimuth, elevation, Doppler frequency shift and time-delay can be obtained simultaneously, and the least number of pulses could be two. This method is computationally efficient even in heavier noised environment, and all estimations are automatically paired in calculation process with no used to any plane sensor array and deal with many spectrum searching. Further more, this algorithm can be targets at the same time only by few sensors. The targets number that can deal with simultaneously is several times to the sensor number, which is the upper limit for normal algorithms such as ESPRIT and MUSIC. These characteristics would be very useful, especially, for aerial systems. Simulations demonstrate the capabilities of this method efficiently. 展开更多
关键词 Pulse cumulating Virtual sensor array Direction Of Arrival (DOA) doppler frequency shift Relative time-delay
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BER Performance of Frequency Domain Differential Demodulation OFDM in Flat Fading Channel
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作者 SONG Lijun TANG Youxi LI Shaoqian HUANG Shunji(National Key Laboratory of Communication,UESTC Chengdu 610054 China) 《Journal of Electronic Science and Technology of China》 2003年第1期32-36,共5页
A closed form expression for the bit error rate (BER) performance of frequency domaindifferential demodulation(FDDD) for orthogonal frequency division multiplexing system in flat fadingchannel is derived.The performan... A closed form expression for the bit error rate (BER) performance of frequency domaindifferential demodulation(FDDD) for orthogonal frequency division multiplexing system in flat fadingchannel is derived.The performance is evaluated by computer simulation and compared with the timedomain differential demodulation(TDDD).The results indicate that the performance of FDDD is betterthan that of TDDD,and the lower band of BER in the former is lower than that of the latter. 展开更多
关键词 orthogonal frequency division multiplexing bit error rate frequency domain differential demodulation doppler shift
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车联网V2I场景下基于GNN的SC-FDMA智能信道估计
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作者 廖勇 尹子松 田肖懿 《电子学报》 EI CAS CSCD 北大核心 2024年第3期772-782,共11页
随着车联网的迅猛发展,车对路基础设施(Vehicle to Infrastructure,V2I)通信对车联网的可靠性和时延提出了更高的要求,而信道估计是接收机高可靠低时延通信的重要保障.为解决传统信道插值算法不能有效拟合V2I信道快时变特性、自适应多... 随着车联网的迅猛发展,车对路基础设施(Vehicle to Infrastructure,V2I)通信对车联网的可靠性和时延提出了更高的要求,而信道估计是接收机高可靠低时延通信的重要保障.为解决传统信道插值算法不能有效拟合V2I信道快时变特性、自适应多普勒频移能力弱和传统神经网络可解释性不强的问题,本文提出基于图神经网络(Graph Neural Network,GNN)的单载波频分多址(Single Carrier-Frequency Division Multiple Access,SC-FDMA)智能信道估计算法.该算法将信道频率响应中的数据点作为图的节点、符号间时域相关性作为边,将图化后的数据送入GraphSAGE信道插值器(GraphSAGE Channel Interpolator,GCI)中,通过边更新、聚合操作、节点更新三大模块进行网络训练,同时采用多普勒频移矢量作为节点特征控制网络拟合不同多普勒条件的信道,使得网络具备可解释性.最后,系统仿真验证了在不同速度环境下算法的有效性和鲁棒性,较线性插值、样条插值以及全连接网络,本文所提GCI在低、中和高速移动环境下具有最优的误码率(Bit Error Rate,BER)和归一化均方误差(Normalized Mean Square Error,NMSE)性能,特别地,在200 km/h高速移动条件下GCI的优势更为明显. 展开更多
关键词 车联网 V2I 双选衰落信道 高速移动 多普勒频移 GNN 信道估计 信道频率响应
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自适应多普勒频移的二相码信号处理方法
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作者 陈华 李勇 +4 位作者 薛卫东 杨宝平 赵勇 高艳辉 岳亮辉 《雷达科学与技术》 北大核心 2024年第3期349-354,共6页
针对二相编码脉冲压缩雷达的信号处理、航天测控系统接收机的解扩需求,在高动态大偏差多普勒频移的场景下,对载波频率搜索捕获的处理方法复杂、计算量较大、实时性较差等问题,本文提出了一种自适应多普勒频移的二相码信号处理方法,在单... 针对二相编码脉冲压缩雷达的信号处理、航天测控系统接收机的解扩需求,在高动态大偏差多普勒频移的场景下,对载波频率搜索捕获的处理方法复杂、计算量较大、实时性较差等问题,本文提出了一种自适应多普勒频移的二相码信号处理方法,在单脉冲的脉内实时提取多普勒频移同相信号及正交信号的波形,并且生成4个片段信号,根据各信号之间固定的时序关系,去除多普勒频移对基带信号的调制,恢复原始基带信号,进而实现脉冲压缩及接收机解扩。MATLAB仿真验证了有效性和可行性。该方法实现简捷、计算量小、实时性好、硬件资源少,对现有相关信号处理领域有一定的指导意义。 展开更多
关键词 多普勒频移 解扩 脉冲压缩 基带信号 二相码
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基于FPGA的大频偏扩频信号快速捕获算法设计
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作者 冯智波 朱彦铭 +2 位作者 刘文重 张俊杰 李迎春 《电子测量技术》 北大核心 2024年第6期34-40,共7页
星载扩频应答机的数据比特与扩频码是异步的,由于传输系统噪声及多普勒频移的影响,会引起接收扩频码与发送扩频码相关峰值的衰减,导致捕获性能下降。传统的捕获技术通常存在算法复杂度高,捕获速度慢,难以适应上百千赫兹大频偏的要求等... 星载扩频应答机的数据比特与扩频码是异步的,由于传输系统噪声及多普勒频移的影响,会引起接收扩频码与发送扩频码相关峰值的衰减,导致捕获性能下降。传统的捕获技术通常存在算法复杂度高,捕获速度慢,难以适应上百千赫兹大频偏的要求等问题。本文提出了一种将扩频序列截成两段分别作相关运算的扩频序列搜索法,并结合信号平方和FFT环进行大频偏锁频的捕获方案,有效抑制了相关峰的衰减,提高了伪码捕获性能。MATLAB仿真及FPGA板级测试表明,本文所提出的扩频信号捕获方案能够对抗高达±300 kHz的多普勒频移,平均捕获时间约为95 ms。另外,该算法的FPGA实现与传统结构相比节省了约47%的LUT、43%的Register以及一半以上的DSP和BRAM资源,在资源受限的实时通信系统中具有很大的应用价值。 展开更多
关键词 多普勒频移 伪码捕获 FPGA
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基于回波模拟法的激光多普勒测速仪示值误差检测方法研究
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作者 鲁伟俊 彭希锋 +3 位作者 陈爽 邓文 赖晖 蒋荣峰 《仪表技术与传感器》 CSCD 北大核心 2024年第7期30-34,共5页
针对高速激光多普勒测速仪(速度上限超过1 km/s)示值误差检测中参考速度难以获得导致测速仪示值误差无法有效检测的问题,提出采用光学回波模拟法对其进行示值误差检测。通过对测速仪的出射光进行光学移频,以此模拟运动物体的激光多普勒... 针对高速激光多普勒测速仪(速度上限超过1 km/s)示值误差检测中参考速度难以获得导致测速仪示值误差无法有效检测的问题,提出采用光学回波模拟法对其进行示值误差检测。通过对测速仪的出射光进行光学移频,以此模拟运动物体的激光多普勒效应,从而解决高速多普勒测速仪检测所需速度源的问题;通过设置波长检测模块与移频量检测模块,获得准确的工作波长与移频频率,进而计算出准确的参考速度信息,保证激光多普勒测速仪示值误差检测的准确性。实验结果表明:基于回波模拟法的激光多普勒测速仪示值误差检测方法,可以实现速度上限高达2.7 km/s的测速仪示值误差的检测,示值误差测量不确定度U_(r)=0.3%(k=2)。实验结果表明基于回波模拟法的激光多普勒测速仪示值误差检测技术具有很好的工程应用前景。 展开更多
关键词 激光多普勒测速仪 回波模拟 示值误差检测 光学移频
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移动物联网通信中的UFMC调制波形优化设计
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作者 闻建刚 华惊宇 +1 位作者 邹园萍 盛彬 《信号处理》 CSCD 北大核心 2024年第4期695-705,共11页
移动物联网(Internet of Things, IoT)通信是6G的关键技术之一,面对多变的地面基站环境,无人机(Unmanned Aerial Vehicle, UAV)辅助通信被认为是物联网通信的重要组成部分,已受到广泛关注。通用滤波器多载波(Universal Filtered Multi-c... 移动物联网(Internet of Things, IoT)通信是6G的关键技术之一,面对多变的地面基站环境,无人机(Unmanned Aerial Vehicle, UAV)辅助通信被认为是物联网通信的重要组成部分,已受到广泛关注。通用滤波器多载波(Universal Filtered Multi-carrier, UFMC)作为一种新型非正交多载波调制技术,继承了正交频分复用(Orthogonal Frequency Division Multiplexing, OFDM)的优势,主要应用在短数据包突发通信场景中,被认为适用于下一代无线物联网通信。但是,在无人机的高速移动环境下,通信信号会遭受显著的多普勒频移影响,产生严重的载波间干扰(Inter Carrier Interference, ICI),导致UFMC系统性能的显著下降。为了缓解ICI问题,本文首先理论分析、推导了存在多普勒频移时UFMC系统的信干噪比(Signal to Interference plus Noise Ratio, SINR)。根据SINR分析,可见将UFMC波形滤波器通带波动优化调控的足够小以及加快过渡带衰减有利于提升系统抗ICI能力。因此,本文提出了基于波形滤波器优化设计的干扰抑制方法,构建了符合UFMC通信需求的波形滤波器最优化设计数学模型,该模型可以有效地调控波形滤波器的通带波动,通过遍历搜索可求解得到使系统误符号率(Symbol Error Rate, SER)相对最优的波形滤波器。在考虑多普勒频移的系统仿真中,SER对比结果表明:与采用传统波形滤波器的UFMC系统相比,本文根据约束最小最大(Constraint Minimax, CMM)准则遍历搜索设计的波形滤波器可以有效地抑制系统ICI从而改善SER。这为未来移动物联网通信系统的波形设计提供了参考。 展开更多
关键词 物联网 通用滤波多载波 多普勒频移 滤波器 误符号率
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子午工程二期电离层高频多普勒监测仪初步观测结果
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作者 郝永强 代国峰 +1 位作者 张东和 肖佐 《地球与行星物理论评(中英文)》 2024年第1期53-65,共13页
子午工程二期计划在漠河、北京、武汉、深圳四地分别建设由一个发射站和三个接收站构成的电离层高频多普勒监测台阵.本文介绍了为此研制的电离层高频多普勒监测仪的进展和试观测期间取得的一些观测结果.通过与电离层测高仪进行交叉对比... 子午工程二期计划在漠河、北京、武汉、深圳四地分别建设由一个发射站和三个接收站构成的电离层高频多普勒监测台阵.本文介绍了为此研制的电离层高频多普勒监测仪的进展和试观测期间取得的一些观测结果.通过与电离层测高仪进行交叉对比,设备的性能和探测能力得到了验证.目前该设备已部署7个站点进行试观测,本文报告了该设备探测到的太阳耀斑导致的电离层扰动、电离层行进式扰动、大尺度电场导致的多站同时扰动等多种现象.未来子午工程二期建成后,该设备将具备我国上空北至漠河、南至广东的电离层扰动监测能力,并与其它探测手段融合发挥空间天气综合监测网络的最大效能. 展开更多
关键词 电离层高频多普勒频移 电离层扰动 子午工程
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A Method to Obtain the Moving Speed of Uncooperative Target Based on Only Two Measurements
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作者 Tao Yu 《Advances in Aerospace Science and Technology》 2024年第1期1-9,共9页
The existing research results show that a fixed single station must conduct three consecutive frequency shift measurements and obtain the target’s moving speed by constructing two frequency difference equations. This... The existing research results show that a fixed single station must conduct three consecutive frequency shift measurements and obtain the target’s moving speed by constructing two frequency difference equations. This article proposes a new method that requires only two consecutive measurements. While using the azimuth measurement to obtain the angular difference between two radial distances, it also conducts two consecutive Doppler frequency shift measurements at the same target azimuth. On the basis of this measurement, a frequency difference equation is first constructed and solved jointly with the Doppler frequency shift equation. By eliminating the velocity variable and using the measured angular difference to obtain the target’s lead angle, the target’s velocity can be solved by using the Doppler frequency shift equation again. The new method avoids the condition that the target must move equidistantly, which not only provides an achievable method for engineering applications but also lays a good foundation for further exploring the use of steady-state signals to achieve passive positioning. 展开更多
关键词 Moving Speed Non-Cooperative Target doppler frequency shift frequency Difference Equation AZIMUTH Steady-State Signal Passive Location
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针对OFDM的低轨卫星资源动态分配算法
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作者 张美蓉 张晨 张更新 《太赫兹科学与电子信息学报》 2024年第9期992-999,共8页
在天地一体化信息网络场景下,卫星通信与地面5G的融合是大势所趋。因此,正交频分复用(OFDM)作为5G空口协议的关键技术,如何高效服务于频带资源受限的低轨卫星通信系统成为研究热点。针对低轨卫星高动态性、系统信道特征、业务时变性以... 在天地一体化信息网络场景下,卫星通信与地面5G的融合是大势所趋。因此,正交频分复用(OFDM)作为5G空口协议的关键技术,如何高效服务于频带资源受限的低轨卫星通信系统成为研究热点。针对低轨卫星高动态性、系统信道特征、业务时变性以及大多普勒频移等特点,提出一种针对OFDM的低轨卫星资源动态分配策略。首先根据3GPP标准规定和最大化频谱效率选择载波间隔,子载波分配前通过剔除劣子信道保证信道的传输性能,通过分簇成倍级减少分配时的循环次数;随后依据用户需求及信道特征对子载波进行贪婪分配;最后对单用户按照比例所分到的功率应用注水原理。仿真结果表明,该算法能有效适应低轨卫星场景,降低算法的复杂度,提高系统容量的同时仍可保证用户需求与传输速率的公平性。 展开更多
关键词 低轨卫星 正交频分复用 多普勒频移 贪婪算法 注水原理
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一种短时猝发GMSK扩频多普勒估计算法研究
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作者 欧家成 廖小海 +2 位作者 张显辉 王慧 许洋 《遥测遥控》 2024年第1期60-66,共7页
多普勒估计是猝发传输背景下的GMSK(Gaussian Filtered Minimum Shift Keying,高斯最小频移键控)扩频通信系统接收端同步过程中的关键一环。针对短时猝发GMSK扩频通信系统信息传输时间极短的特点,搭建了系统接收端同步段结构,并以此为... 多普勒估计是猝发传输背景下的GMSK(Gaussian Filtered Minimum Shift Keying,高斯最小频移键控)扩频通信系统接收端同步过程中的关键一环。针对短时猝发GMSK扩频通信系统信息传输时间极短的特点,搭建了系统接收端同步段结构,并以此为基础设计了适应该短时猝发同步段结构的多普勒估计算法,建立了短时猝发多普勒估计算法模型,推导该算法公式的同时对算法模型进行了理论分析,详细阐述了该算法进行多普勒估计的实现过程,并对该算法进行仿真实验。实验结果表明,该算法在信噪比为1 dB时,多普勒估计准确度可达到97.2%,信噪比≥3 dB时,准确度均能在99%及以上,该结果验证了该算法应用在猝发传输背景下的GMSK扩频通信系统中的有效性、可行性,同时也表明当通信系统处于弱信号的条件下时,该多普勒估计算法性能依然能达到一个较为优异的准确度值。 展开更多
关键词 多普勒估计 多普勒频移 扩频通信 GMSK 猝发传输
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毫米波Doppler传感器在心脏监护系统中的应用
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作者 昂志敏 《合肥工业大学学报(自然科学版)》 CAS CSCD 1998年第S1期37-41,共5页
分析探讨毫米波多普勒前端作为传感器在心脏监护系统中的应用,简述了其基本原理并论述了毫米波Doppler前端传感器的几种方案及整体监护系统的基本组成。
关键词 多普勒效应 濒移 心脏监护 信号处理
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基于Doppler的连续油管长度在线测量系统
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作者 刘丽群 赵周礼 闻邦椿 《中国工程机械学报》 2012年第1期115-119,共5页
设计了一种基于激光Doppler效应的连续油管长度在线测量系统.该系统通过接收运动油管表面的散射光,经过数据采集和信号处理,测量出多普勒频移,进而求出油管运动的瞬时速度,通过积分最终得到下井油管的长度.该系统具有测量精度高、性能... 设计了一种基于激光Doppler效应的连续油管长度在线测量系统.该系统通过接收运动油管表面的散射光,经过数据采集和信号处理,测量出多普勒频移,进而求出油管运动的瞬时速度,通过积分最终得到下井油管的长度.该系统具有测量精度高、性能稳定且容易实现的特点,适合油田现场作业的要求,具有广阔的应用前景. 展开更多
关键词 光振动 频移 激光多普勒效应 油管长度测量
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ATTITUDE RATE ESTIMATION BY GPS DOPPLER SIGNAL PROCESSING 被引量:1
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作者 HeSide GuoZhenyu 《Journal of Electronics(China)》 2003年第1期13-19,共7页
A method is presented for near-Earth spacecraft or aviation vehicle's attitude rate estimation by using relative Doppler frequency shift; of the Global Positioning System (GPS) carrier. It comprises two GPS receiv... A method is presented for near-Earth spacecraft or aviation vehicle's attitude rate estimation by using relative Doppler frequency shift; of the Global Positioning System (GPS) carrier. It comprises two GPS receiving antennas, a signal processing circuit and an algorithm. The whole system is relatively simple, the cost and weight, as well as power consumption, are very low. 展开更多
关键词 Attitude rate determination Global positioning system SATELLITE doppler frequency shift
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The Doppler Frequency Shift Calculation Model for Space VLBI
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作者 郑勇 钱志瀚 《Chinese Science Bulletin》 SCIE EI CAS 1993年第8期654-656,共3页
关键词 SPACE VLBI SYNCHRONOUS doppler frequency shift
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