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卫星扩频测控体制研究 被引量:8
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作者 朱雪萍 刘锐梅 +2 位作者 金野 陶成华 张立华 《无线电工程》 2006年第3期39-41,共3页
介绍了USB微波统一测控系统、连续波测量系统、GPS原理。对中低轨卫星扩频测控采用的测控体制作了相应的论述与设计。提出中低轨卫星测控采用星地上下行信号相干(包括载波相干、伪码相干)方式,使星上应答机发射的下行频率与地面站发射... 介绍了USB微波统一测控系统、连续波测量系统、GPS原理。对中低轨卫星扩频测控采用的测控体制作了相应的论述与设计。提出中低轨卫星测控采用星地上下行信号相干(包括载波相干、伪码相干)方式,使星上应答机发射的下行频率与地面站发射的上行频率同步,消除星地钟差,完成卫星的测速、测距以及遥测遥控任务,并阐述了星地扩频测控设备的组成和工作原理。 展开更多
关键词 扩频 测控 GPS 相干 非相干
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A hypersonic target coherent integration detection algorithm based on Doppler feedback 被引量:6
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作者 LI Lin WANG Guohong +1 位作者 SUN Dianxing ZHANG Xiangyu 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2020年第1期85-94,共10页
The traversal search of multi-dimensional parameter during the process of hypersonic target echo signal coherent integration,leads to the problem of large amounts of calculation and poor real-time performance.In view ... The traversal search of multi-dimensional parameter during the process of hypersonic target echo signal coherent integration,leads to the problem of large amounts of calculation and poor real-time performance.In view of these problems,a modified polynomial Radon-polynomial Fourier transform(MPRPFT)hypersonic target coherent integration detection algorithm based on Doppler feedback is proposed in this paper.Firstly,the Doppler estimation value of the target is obtained by using the target point information obtained by subsequent non-coherent integration detection.Then,the feedback adjustment of the coherent integration process is performed by using the acquired target Doppler estimation value.Finally,the coherent integration is completed after adjusting the search interval of compensation.The simulation results show that the algorithm can effectively reduce the computational complexity and improve the real-time performance on the basis of the effective coherent integration of hypersonic target echo signals. 展开更多
关键词 hypersonic target coherent integration non-coherent integration Doppler estimation feedback adjustment
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相参雷达与非相参雷达的差异分析 被引量:8
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作者 叶昊儒 《现代电子技术》 2010年第3期17-19,共3页
针对相参雷达和非相参雷达的概念进行阐述。通过详细分析两种体制雷达在应用上的主要区别,侧重介绍相参雷达的优点。相参性方面重点介绍多普勒效应具有的特性,从信号接收和信号处理上重点讨论了相参性雷达拥有的速度测量功能,在速度模... 针对相参雷达和非相参雷达的概念进行阐述。通过详细分析两种体制雷达在应用上的主要区别,侧重介绍相参雷达的优点。相参性方面重点介绍多普勒效应具有的特性,从信号接收和信号处理上重点讨论了相参性雷达拥有的速度测量功能,在速度模糊和距离模糊上详细比较了两者的差别。通过实践证明,相参雷达的应用范围比非相参雷达的范围广阔得多,但价格不菲。 展开更多
关键词 相参 非相参 多普勒效应 速度测量
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Long term integration of radar signals with unknown Doppler shift for ubiquitous radar 被引量:4
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作者 Qinglong Bao Zengping Chen Yue Zhang Jian Yang 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2011年第2期219-227,共9页
Ubiquitous radar is a new radar system that provides continuous and uninterrupted multifunction capability within a coverage volume. Continuous coverage from close-in "pop-up" targets in clutter to long-range target... Ubiquitous radar is a new radar system that provides continuous and uninterrupted multifunction capability within a coverage volume. Continuous coverage from close-in "pop-up" targets in clutter to long-range targets impacts selection of waveform parameters. The coherent processing interval (CPI) must be long enough to achieve a certain signal-to-noise ratio (SNR) that ensures the efficiency of detection. The condition of detection in the case of low SNR is analyzed, and three different cases that would occur during integration are discussed and a method to determine the CPI is presented. The simulation results show that targets detection with SNR as low as -26 dB in the experimental system can possibly determine the CPI. 展开更多
关键词 ubiquitous radar low signal-to-noise ratio (SNR) coherent processing interval (CPI) coherent integration non-coherent integration.
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超宽带穿墙雷达非相干成像方法 被引量:5
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作者 陈洁 方广有 李芳 《中国科学院研究生院学报》 CAS CSCD 2007年第6期829-834,共6页
超宽带穿墙成像雷达作为一种能够隔墙探测和定位的新型雷达系统,在很多领域得到应用.穿墙成像雷达有非相干方法和相干方法2种成像方法.本文采用一发二收的天线组合形式,用非相干成像方法,研究了在无墙体和有墙体2种情况下目标的定位,分... 超宽带穿墙成像雷达作为一种能够隔墙探测和定位的新型雷达系统,在很多领域得到应用.穿墙成像雷达有非相干方法和相干方法2种成像方法.本文采用一发二收的天线组合形式,用非相干成像方法,研究了在无墙体和有墙体2种情况下目标的定位,分析了雷达的方位向分辨率,并通过二维FDTD仿真验证了目标定位方法. 展开更多
关键词 超宽带 穿墙成像 非相关 三角定位
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A Simple Method to Derive Minimal Cut Sets for a Non-coherent Fault Tree 被引量:2
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作者 Takehisa Kohda 《International Journal of Automation and computing》 EI 2006年第2期151-156,共6页
Minimal cut sets (or prime implicants: minimal combinations of basic event conditions leading to system failure) are important information for reliability/safety analysis and design. To obtain minimal cut sets for ... Minimal cut sets (or prime implicants: minimal combinations of basic event conditions leading to system failure) are important information for reliability/safety analysis and design. To obtain minimal cut sets for general non-coherent fault trees, including negative basic events or multi-valued basic events, a special procedure such as the consensus rule must be applied to the results obtained by logical operations for coherent fault trees, which will require more steps and time. This paper proposes a simple method for a non-coherent fault tree, whose top event is represented as an AND combination of monotonic sub-trees. A "monotonic" sub-tree means that it does not have both positive and negative representations for each basic event. It is proven that minimal cut sets can be obtained by a conventional method for coherent fault trees. An illustrative example of a simple event tree analysis shows the detail and characteristics of the proposed method. 展开更多
关键词 non-coherent fault trees monotonic sub-trees minimal cut sets.
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New method for passive radar seeker to antagonize non-coherent radar decoy 被引量:4
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作者 Weijian Si,Xicai Si,and Zhiyu Qu College of Information and Communication Engineering,Harbin Engineering University,Harbin 150001,P.R.China 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2010年第3期397-403,共7页
Using super resolution direction of arrival(DOA) estimation algorithm to reduce the resolution angle is an effective method for passive radar seeker(PRS) to antagonize non-coherent radar decoy.Considering the powe... Using super resolution direction of arrival(DOA) estimation algorithm to reduce the resolution angle is an effective method for passive radar seeker(PRS) to antagonize non-coherent radar decoy.Considering the power and correlation property between radar and non-coherent decoy,an improved subspace DOA estimation method based on traditional subspace algorithm is proposed.Because this new method uses the invariance property of noise subspace,compared with traditional MUSIC algorithm,it shows not only better resolution in condition of closely spaced sources,but also superior performance in case of different power or partially correlated sources.Using this new method,PRS can distinguish radar and non-coherent decoy with good performance.Both the simulation result and the experimental data confirm the performance of the method. 展开更多
关键词 radar countermeasures passive radar seeker(PRS) non-coherent decoy direction of arrival(DOA) estimation.
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一种非相参雷达回波信号模拟器的设计 被引量:5
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作者 黄小娟 李康 雒海潮 《火控雷达技术》 2012年第3期37-39,43,共4页
分析雷达回波特性,从非相参信号模拟开始,提出一种雷达回波模拟器的实现方法。该方法可以利用已知或计算机产生的目标信息运算获得回波信号数据,通过FPGA或DSP芯片控制DDS产生中频回波信号。这种方法具有极大的灵活性和通用性,只要改变... 分析雷达回波特性,从非相参信号模拟开始,提出一种雷达回波模拟器的实现方法。该方法可以利用已知或计算机产生的目标信息运算获得回波信号数据,通过FPGA或DSP芯片控制DDS产生中频回波信号。这种方法具有极大的灵活性和通用性,只要改变计算机回波信号计算模型或参数,即可实现不同回波信号的模拟。 展开更多
关键词 非相参 回波模拟器 DDS
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Favourable and Unfavourable EMF Frequency Patterns in Cancer:Perspectives for Improved Therapy and Prevention 被引量:3
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作者 Dirk K.F.Meijer Hans J.H.Geesink 《Journal of Cancer Therapy》 2018年第3期188-230,共43页
Carcinogenesis fits in a frequency pattern of electromagnetic field (EMF) waves, in which a gradual loss of cellular organization occurs. Such generation of cancer features can be inhibited by adequate exposure to coh... Carcinogenesis fits in a frequency pattern of electromagnetic field (EMF) waves, in which a gradual loss of cellular organization occurs. Such generation of cancer features can be inhibited by adequate exposure to coherent electromagnetic frequencies. However, cancer can also be initiated and promoted at other distinct frequencies of electromagnetic waves. Both observations were revealed by analyzing 100 different EMF frequency data reported in a meta-analyses of 123 different, earlier published, biomedical studies. The studied EM frequencies showed a fractal pattern of 12 beneficial (anti-cancer) frequencies, and 12 detrimental (cancer promoting) frequencies, that form the central pattern of a much wider self-similar EMF spectrum of cancer inhibiting or promoting activities. Inhibiting of the cancer process, and even curing of the disease, can thus be considered through exposure to the coherent type of EM fields. Stabilization of the disease can be understood by constructive resonance of macromolecules in the cancer cell with the externally appied coherent EMF field frequencies, called solitons/polarons. The latter, for instance, have been shown earlier to induce repair in DNA/RNA conformation and/or epigenetic changes. The field of EMF treatment of cancer disorders is rapidly expanding and our studies may invite further experimental and clinical studies in which systematically various potential EMF treatment protocols could be applied, with combined and modulated frequencies, to obtain even more efficient EMF anti-cancer therapies. 展开更多
关键词 Cancer Therapy coherent EMF Frequencies non-coherent EMF Frequencies Electromagnetic Fields SOLITONS non-Ionizing EM Radiation Frohlich Davydov
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MICROSTRUCTURE OF DIFFERENTLY TREATED Al-Mg-Sc-Zr ALLOYS 被引量:1
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作者 Jie Zhang Zhimin Yin +2 位作者 Yonghong Zhang Yongzheng Gao Qinglin Pan 《Journal of Central South University》 SCIE EI CAS 1997年第1期24-27,共4页
The microstructures of different treated Al-5Mg-0.5Sc-0. 1Zr alloys have been studied with opticalmicroscopy and transmission electron microscope (TEM). Coherent particles with the matrix were found inas-cast sample. ... The microstructures of different treated Al-5Mg-0.5Sc-0. 1Zr alloys have been studied with opticalmicroscopy and transmission electron microscope (TEM). Coherent particles with the matrix were found inas-cast sample. composite Al3Sc/Al3Zr particles were found after 13 h homogenized treatment under 470℃.Coherent precipitates pinned dislocations and low-angle grain boundaries. and then restrained recrystallization. All kinds of particles of different treatments were not larger than 40nm. After high-temperaturestabilization treatments, most particles remain coherent with the matrix. The reasons of microstructurechange at different treated conditions have been analyzed. 展开更多
关键词 Al-Mg-Sc-Zr alloy MICROSTRUCTURE Al_3 (Sc Zr) coherent and non-coherent
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基于遗传算法的UWB信号非相干捕获方法 被引量:4
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作者 杨志华 张钦宇 张乃通 《电子学报》 EI CAS CSCD 北大核心 2010年第7期1568-1573,共6页
本文针对动态信噪比环境超宽带(UWB,Ultra WideBand)信号的非相干捕获,提出了一种基于遗传算法的信号捕获方案.以遗传算法结合在线估计接收信噪比,搜索积分窗口长度与定时位置的参数组合,实现系统要求的比特错误概率.该方法解决了传统... 本文针对动态信噪比环境超宽带(UWB,Ultra WideBand)信号的非相干捕获,提出了一种基于遗传算法的信号捕获方案.以遗传算法结合在线估计接收信噪比,搜索积分窗口长度与定时位置的参数组合,实现系统要求的比特错误概率.该方法解决了传统捕获方案在未知信噪比条件下积分长度无法择优选取以及捕获门限难于设定的问题.仿真结果表明,基于遗传算法的二维参数捕获方法与传统Look and Jump by Ksteps算法相比有效的提高了未知信噪比条件下的系统捕获性能,拓展了UWB非相干系统的应用范围. 展开更多
关键词 超宽带 非相干 信号捕获 遗传算法 参数组合
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星载AIS信号的非相干检测 被引量:4
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作者 方婷 马社祥 孟鑫 《计算机仿真》 CSCD 北大核心 2013年第11期177-181,共5页
针对星载AIS系统存在多普勒频移较大、信道时变较快,同时多用户干扰严重等问题,提出了一种新的简化的基于Viterbi算法的非相干序列检测方法,以连续多个符号为观测窗,将接收信号经过Laurent分解的主要分量作匹配滤波,无需白化滤波,有效... 针对星载AIS系统存在多普勒频移较大、信道时变较快,同时多用户干扰严重等问题,提出了一种新的简化的基于Viterbi算法的非相干序列检测方法,以连续多个符号为观测窗,将接收信号经过Laurent分解的主要分量作匹配滤波,无需白化滤波,有效避免了相关长度对检测性能的影响,系统复杂度显著降低。算法基于最大似然准则给出了解码的代价函数,利用Viterbi算法进行译码。仿真结果表明,改进方法具有良好的检测性能,当观测长度为6个符号时,性能与理想相干检测性能相差大约1dB,优于传统二比特差分解码10dB左右,同时也适用于存在多用户干扰的情况。 展开更多
关键词 星载自动识别系统 检测 非相干 维特比 多符号
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自适应非相干矢量跟踪环路设计 被引量:4
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作者 刘红光 傅金琳 +2 位作者 金天 吴雨航 纪元法 《中国惯性技术学报》 EI CSCD 北大核心 2018年第3期323-329,共7页
针对导航接收机相关累加结果受导航电文数据比特跳变影响的问题,提出了一种自适应非相干矢量跟踪环路。通过在传统矢量跟踪环路中引入非相干频率/码鉴别器,使非相干与相干结合的相关器累加结果不再受比特跳变的影响。对非相干积分的灵... 针对导航接收机相关累加结果受导航电文数据比特跳变影响的问题,提出了一种自适应非相干矢量跟踪环路。通过在传统矢量跟踪环路中引入非相干频率/码鉴别器,使非相干与相干结合的相关器累加结果不再受比特跳变的影响。对非相干积分的灵敏度和动态性能进行了理论分析和仿真验证,同时给出了在一定动态范围内环路积分时间的优化选择方案,实现了环路积分时间在1~10 ms及非相干次数在1~10次的自适应调整设置。实验结果证明,自适应矢量非相干环路提升跟踪灵敏度约6 d B,非相干方法提高了矢量跟踪环路性能。 展开更多
关键词 非相干 矢量跟踪 灵敏度 动态性能
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相对强度噪声对微波光子链路性能影响规律研究 被引量:3
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作者 田中成 《半导体光电》 CAS 北大核心 2016年第6期911-916,共6页
激光器的相对强度噪声(RIN)在微波光子链路中转换为噪声功率,进而影响链路的动态范围。文章建立了基本结构的非相干和相干微波光子链路的动态范围(SFDR)模型,并通过仿真对比分析了激光器的RIN对这两种链路结构的影响。在光器件的性能水... 激光器的相对强度噪声(RIN)在微波光子链路中转换为噪声功率,进而影响链路的动态范围。文章建立了基本结构的非相干和相干微波光子链路的动态范围(SFDR)模型,并通过仿真对比分析了激光器的RIN对这两种链路结构的影响。在光器件的性能水平较低时,非相干微波光子链路能获得更大的SFDR;随着光器件性能水平的提升,相干微波光子链路的SFDR将超过非相干微波光子链路。而在目前典型的器件参数条件下,两种链路的理论SFDR都能达到120dB·Hz^(2/3)左右。 展开更多
关键词 相对强度噪声 非相干 相干 微波光子链路 动态范围
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Signal acquisition of Luojia-1A low earth orbit navigation augmentation system with software defined receiver 被引量:1
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作者 Liang Chen Xiangchen Lu +5 位作者 Nan Shen Lei Wang Yuan Zhuang Ye Su Deren Li Ruizhi Chen 《Geo-Spatial Information Science》 SCIE EI CSCD 2022年第1期47-62,共16页
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
关键词 coherent integration differential coherent integration Low Earth Orbit(LEO) non-coherent integration navigation augmentation signal acquisition
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Novel non-coherent integration method using binary phase-coded radar signal 被引量:2
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作者 田黎育 何苗 +1 位作者 刘斌 傅雄军 《Journal of Beijing Institute of Technology》 EI CAS 2013年第1期60-66,共7页
The m series with 511 bits is taken as an example being applied in non-coherent integra- tion algorithm. A method to choose the bi-phase code is presented, which is 15 kinds of codes are picked out of 511 kinds of m s... The m series with 511 bits is taken as an example being applied in non-coherent integra- tion algorithm. A method to choose the bi-phase code is presented, which is 15 kinds of codes are picked out of 511 kinds of m series to do non-coherent integration. It is indicated that the power in- creasing times of larger target sidelobe is less than the power increasing times of smaller target main- lobe because of the larger target' s pseudo-randomness. Smaller target is integrated from larger tar- get sidelobe, which strengthens the detection capability of radar for smaller targets. According to the sidelobes distributing characteristic, a method is presented in this paper to remove the estimated sidelobes mean value for signal detection after non-coherent integration. Simulation results present that the SNR of small target can be improved approximately 6. 5 dB by the proposed method. 展开更多
关键词 binary phase-coded signal non-coherent integration code agility peak sidelobe level(PSL) mainlobe-peak sidelobe ratio
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An energy detection receiver for non-coherent IR-UWB 被引量:2
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作者 蔡力 黄鲁 +2 位作者 傅忠谦 杨静儿 王卫东 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2011年第6期96-103,共8页
A non-coherent receiver for impulse radio ultra-wide band(IR-UWB)is presented.The proposed receiver front-end consists of a high gain LNA,a high frequency detector and an intermediate frequency(IF)amplifier to amp... A non-coherent receiver for impulse radio ultra-wide band(IR-UWB)is presented.The proposed receiver front-end consists of a high gain LNA,a high frequency detector and an intermediate frequency(IF)amplifier to amplify the recovered signal and drive an external test instrument.To meet the requirements of high gain and a low noise figure(NF)under moderate power consumption for the LNA,capacitor cross coupled(CCC)and current reuse techniques were adopted.The detector consists of a squarer and an integrator.The overall circuit consumes 41.2mA current with a supply voltage of 1.8 V at a 400 MHz pulse rate.The resulting energy efficiency is 0.19 nJ/pulse.A chip prototype is implemented in 0.18-μm CMOS.The die area is 2.1×1.4 mm^2 and the active area is 1.7×0.98 mm^2. 展开更多
关键词 RECEIVER IR-UWB non-coherent LNA DETECTOR
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Target estimation using MIMO radar with multiple subcarriers 被引量:2
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作者 Min Jiang Jianguo Huang +1 位作者 Yong Jin Jing Han 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2012年第1期57-62,共6页
This paper analyzes the effect of waveform parame- ters on the joint target location and velocity estimation by a non- coherent multiple input multiple output (MIMO) radar transmitting multiple subcarriers signals. ... This paper analyzes the effect of waveform parame- ters on the joint target location and velocity estimation by a non- coherent multiple input multiple output (MIMO) radar transmitting multiple subcarriers signals. How the number of subcarriers in- fluences the estimation accuracy is illustrated by considering the joint Cramer-Rao bound and the mean square error of the maxi- mum likelihood estimate. The non-coherent MIMO radar ambiguity function with multiple subcarriers is developed and investigated by changing the number of subcarriers, the pulse width and the frequency spacing between adjacent subcarriers. The numerical results show that more subcarriers mean more accurate estimates, higher localization resolution, and larger pulse width results in a worse performance of target location estimation, while the fre- quency spacing affects target location estimation little. 展开更多
关键词 target estimation non-coherent multiple input multi- ple output (MIMO) radar multiple subcarrier waveform parameter ambiguity function (AF).
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雷达三点源诱偏系统布局方案研究 被引量:3
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作者 况付生 花兴来 张伟 《舰船电子工程》 2009年第9期99-101,共3页
在假设两种典型的非相干三点源布局方案参数未知的情况下,通过对反辐射导弹在非相干三点源诱饵情况下的动态飞行过程的分析,对两种布局的诱偏效果进行评估,最后得到三点源的有效布局方案参数。
关键词 三点源 布局 非相干
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一种新的非相干超宽带自适应同步方法的仿真与分析 被引量:1
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作者 谷俊嵘 金明录 刘婷婷 《系统仿真学报》 CAS CSCD 北大核心 2009年第8期2350-2354,共5页
超宽带系统使用纳秒级的短脉传输数据,能够克服短距离通信中的多径影响,特别适合短距离高速数据通信。针对超宽带系统的快速低复杂度同步问题,基于非相干脉冲超宽带系统,结合相干超宽带系统中的一些快速捕获算法,提出一种新的快速同步... 超宽带系统使用纳秒级的短脉传输数据,能够克服短距离通信中的多径影响,特别适合短距离高速数据通信。针对超宽带系统的快速低复杂度同步问题,基于非相干脉冲超宽带系统,结合相干超宽带系统中的一些快速捕获算法,提出一种新的快速同步方法。在子积分窗口部分重叠时,该同步方法能够比文献[1]中的方法更快速达到同步。经仿真验证,本方法在同步性能上均优于现有方法。 展开更多
关键词 UWB 非相干 同步 自适应
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