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一种双通道中频数字接收机的硬件设计实现 总被引:1,自引:1,他引:0
在电子对抗领域中,雷达信号的信息是信号分选、威胁识别、引导干扰的重要参数.与传统的模拟接收技术相比,数字接收机具有高分辨率、高可靠性、抗干扰能力强、灵活可变等许多优点.宽带、大动态范围、高灵敏度的数字接收机在电子对抗领域中有着广泛的应用前景.根据中频采样和数字下变频的基本原理,介绍了一种双通道中频数字接收机的硬件设计与实现方案.模拟信号经高速A/D采样后直接由FPGA进行信号处理.结果表明,系统具有成本低、精度高、结构简单等优良性能,可以满足实际需要. 相似文献
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谢先明 《重庆邮电大学学报(自然科学版)》2006,18(4):479-481
分析了基于软件无线电的宽带数字中频接收机中的关键技术-带通采样下变频技术、数字下变频技术、多速率处理技术,并实现了欠采样技术条件的软件系统仿真。由此可见,在现有条件下实现宽带数字中频接收机是可行的。 相似文献
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谢先明 《重庆邮电学院学报(自然科学版)》2006,18(4):479-481,492
分析了基于软件无线电的宽带数字中频接收机中的关键技术一带通采样下变频技术、数字下变频技术、多速率处理技术,并实现了欠采样技术条件的软件系统仿真。由此可见,在现有条件下实现宽带数字中频接收机是可行的。 相似文献
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爱现有技术水平的翻约,在目前的信号变频体制中大部分是首先将射频信号通过一次或者几次的模拟下变频转换到中频上,在中频对信号数字化,然后再进行数字下变频.随着数字通信技术的发展,无线通信技术的逐渐成熟,对无线设备数字带宽的要求也越来越高,所以,有必要对带宽较宽信号的数字下变频进行研究. 相似文献
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《哈尔滨商业大学学报(自然科学版)》2016,(3)
设计了一种高速7通道的数字接收机系统.该系统的工作流程为雷达信号经微波前端转变成雷达中频信号,中频信号经过ADC芯片转化成数字量,数字量经FPGA的解串、混频、滤波等操作转换成信号的实部和虚部.采集数据经FPGA处理后通过EMIF接口传送至DSP,并完成后续的复杂信号处理.该系统的采集速率为360MSPS.经过实测检验该系统实现了7通道的高速数据采集和处理传输,实现了较高性能的同步.经过对ADC芯片采集数据性能的测试,数据采集达到了较高的性能.该设计完全符合设计要求,能够满足当前电磁环境复杂环境下的雷达信号处理分析的需求. 相似文献
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无线发射系统被广泛的应用,对它的射频前端进行研究十分重要.该射频前端包括滤波器模块、混频器模块、放大器模块、功放模块、天线模块,方便对后期基于FPGA数字中频部分产生的10.7 MHz中频信号进行处理,然后得到具有一定功率的433.92 MHz射频信号,并有效发射.最后对各个模块进行调试与测试,验证了该射频前端设计的正确性,实现了对数字中频输出声音信号的发射转换. 相似文献
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Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness. 相似文献
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理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。 相似文献
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As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death. 相似文献
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Miao Maosheng 《华南师范大学学报(自然科学版)》2014,(6)
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula- 相似文献
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Yang Weitao 《华南师范大学学报(自然科学版)》2014,46(6):137-138
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re- 相似文献
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Bernard Kirtman 《华南师范大学学报(自然科学版)》2014,(6)
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that 相似文献
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Michael Springborg 《华南师范大学学报(自然科学版)》2014,(6):136
For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the 相似文献
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Zhu Chaoyuan 《华南师范大学学报(自然科学版)》2014,46(6):140-140
Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of 相似文献
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《上海师范大学学报(自然科学版)》2014,(5):550
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with 相似文献