共查询到20条相似文献,搜索用时 109 毫秒
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针对短波通信传统自动链路建立技术选频准确性低、建链效率低、资源利用率低等问题,提出一种基于短波数字信道化接收的通信探测一体化快速建链方法。利用数字信道化技术实现短波全频段并行接收。设计了通信探测一体化波形,解决建链过程中波形切换带来的时间冗余和设备兼容问题。设计了探测即建链的快速建链方案,实现复杂电磁环境下的快速稳健通联。实测结果表明,信道化结构能够增强建链系统的接收性能,建链方案相较于传统建链方案有明显优势,信道参数估计方法有较高的估计精度,验证了所提方法在真实短波信道环境的适用性。 相似文献
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短波通信带宽受限,容易受到多普勒效应的影响,从而影响传统单/多载波波形的传输性能。正交时频空(Orthogonal Time Frequency Space,OTFS)是近年来涌现的新型传输波形,能够适用于高多普勒扩展的无线传输场景。进而,基于短波信道首次验证了OTFS波形的传输能力,在发射端提出了支持OTFS波形的信号发生机制,并在接收端实现了基于块最小均方误差的信号检测算法。最后,在典型短波信道条件下,通过计算机仿真,比较了OTFS和单/多载波波形的传输性能。结果表明,OTFS波形在高多普勒扩展下具有性能优势,从而验证了OTFS波形在短波通信中的应用潜力。 相似文献
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基于Watterson短波信道模型,构建了Turbo码在短波信道下的设计和仿真方法。在高信噪比区域中,推导出了不同信道条件下Turbo码的性能界公式;在低信噪比区域中,用Matlab仿真了短波信道下不同的信道条件及Turbo码的主要设计参数对其性能的影响,并给出了Turbo码在短波信道下的设计参数,为实际工程中的应用提供参考。 相似文献
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在通信系统的仿真中,信道模拟器对真实信道的逼近程度,直接影响到通信系统仿真所得性能参数的有效性。因而,开发性能良好的短波信道模拟器是十分必要的。详细叙述了短波电离层信道Watterson模型的原理,根据军标所给短波信道参数,提出了具体的短波信道模拟器实现方案,并给出了计算机仿真结果,较好地模拟了短波信道的时间选择性衰落特性和频率选择性衰落特性。 相似文献
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双多进制正交扩频(Dual M-ary Orthogonal Spread Spectrum)技术是一种高频谱效率的扩频技术,而短波通信在通信领域具有其他通信手段无法替代的地位。阐述了双多进制正交扩频系统的基本原理,介绍了美军现役短波调制解调器标准MIL-STD-188-110B中的低速串行75 b/s波形。设计了基于双多进制扩频技术的短波低速改进波形,并与美军标MIL-STD-188-110B中的低速串行75 b/s波形进行了对比仿真。仿真结果表明,与美军标波形相比,改进波形的BER性能在AWGN信道及衰落信道下均有明显提升。 相似文献
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Shengjuan Cheng Wen-Qin Wang H. C. So 《Multidimensional Systems and Signal Processing》2017,28(1):237-249
In multiple-input multiple-output radar systems, the employed waveforms should have a large time-bandwidth product, good correlation property and satisfactory ambiguity function performance. This paper proposes a orthogonal frequency division multiplexing (OFDM) chirp waveform diversity design scheme with sparse modeling and joint optimization of the waveform code matrix and amplitude matrix. First, we formulate the waveform diversity design as a mathematical optimization problem with sparse modeling and optimally design a code matrix to select the hopping frequencies for each waveform. Thereafter, the waveform amplitudes are adaptively designed by minimizing the cross-correlation peaks with genetic algorithm. The proposed method can easily generate multiple pseudo-orthogonal waveforms with satisfactory correlation and ambiguity function performance. Additionally, the impacts of waveform number, hopping frequency interval and selectable frequency index are discussed. The superiority of the proposed OFDM chirp waveform design over existing methods is verified by extensive simulation results. 相似文献
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Chang-Ming Liaw Wen-Chin Yu Thin-Huo Chen 《Industrial Electronics, IEEE Transactions on》2002,49(3):587-594
The random vibration control of an inverter-fed electrodynamic shaker is presented in this paper. First, the dynamic model of the shaker is found and a current-controlled pulsewidth modulation inverter is designed and implemented. The feedback controller is augmented with a command feedforward controller and a disturbance feedforward controller to let the armature exciting current have low harmonic content and possess excellent waveform tracking performance. Then, an acceleration controller and its random vibration command are arranged. In the proposed acceleration control scheme, a command feedforward controller and a robust disturbance feedforward controller are also employed to let the shaker have close random acceleration command waveform tracking control performance, and the performance be insensitive to the system parameter variations. It follows that the acceleration control with desired frequency response in a vibration test could be achieved through properly setting the command signal. The effectiveness of the proposed control scheme is verified by simulation and measured results 相似文献
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为提高电子战中弹载雷达检测性能,该文提出基于纳什均衡的雷达波形设计方法。首先建立电子战条件下雷达与干扰信号博弈模型,基于最大化信干噪比(SINR)准则,分别设计了雷达和干扰的波形策略;然后通过数学推导论证了博弈纳什均衡解的存在性,设计了一种重复剔除严格劣势的多次迭代注水方法来实现纳什均衡;通过二步注水法推导了非均衡的maxmin优化方案;最后通过仿真实验测试不同策略下雷达检测性能。仿真结果证明,基于纳什均衡的雷达信号设计有助于提升博弈条件下雷达检测性能,对比未博弈时,雷达检测概率最高可提升12.02%,较maxmin策略最高可提升3.82%,证明所设计的纳什均衡策略更接近帕累托最优。 相似文献
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介绍了一种基于碲镉汞红外短波相机的图像实时采集与显示系统。以基于
碲镉汞短波红外探测器以及FPGA+DSP硬件结构,且具有手动调焦、调节积分时间和增减衰减
片等多种功能的红外短波凝视相机作为采集系统的基础,以Camera Link接口连接线作为传输通道,采
用兼容PCI Express x4总线的采集卡实现了红外图像的实时快速采集和显示。实验中,设计了图
像采集与显示界面,以实现对相机的实时控制和对采集图像的调整;设计了一种图像回放软件,以完成
存储图像检验和后期图像处理等工作。实验结果证明,该系统的性能稳定可靠,实时采集、传输和存
储功能完备准确,因此具有很高的工程实用价值。 相似文献
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Mingxuan Zhang Weiwei Miao Jian Dang Zhengyang Ding Shaqian Zhang Zeng Zeng Hao Tang Mengting Wu Zaichen Zhang Liang Wu 《International Journal of Communication Systems》2020,33(1)
Universal filtered multicarrier (UFMC) is a promising new waveform that eliminates cyclic prefix and performs filtering on a chunk of successive subcarriers. Therefore, it is suitable for applications with requirements on high spectral efficiency and low latency. However, the limited bandwidth may be an obstacle for reliable communication in frequency selective channels. This paper proposes a new transmitter structure for uplink wireless communication system based on UFMC waveform. The basic idea is to allow a user to transmit its information on more than one subband simultaneously, increasing its robustness against frequency selectivity. To eliminate the multiuser interference brought by the overlapped transmission strategy, an iterative receiver with parallel interference cancellation is designed. Rate analysis is provided to reveal the rationale of the proposed scheme. Simulations on the symbol error rate performance are conducted to validate the transceiver design. It is found that the proposed scheme outperforms existing UFMC design without sacrificing any other performance metrics with only moderately increased complexity. 相似文献
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针对雷达多径干扰问题,提出一种基于正交频分复用(OFDM)的多发多收合成孔径雷达(MIMO-SAR)抗多径波形设计方法。该方法基于频率分集原理,设计循环移位OFDM-LFM波形提升OFDM波形有效带宽,并针对该波形设计MIMO平台收发模型,结合多通道正交波形空时编码(STC)方案实现多通道接收信号分离,该波形设计方案对SAR多径干扰抑制有效。该方法可以解决多径干扰导致的目标分辨率低及虚假目标问题,在机载SAR高分辨率成像、车载SAR城市探测与智能驾驶等方面具备广阔应用前景。 相似文献
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Concerns control of an electrodynamic shaker for vibration-proof testing of electronic products. An acceleration controller for such a shaker fed by a switching-mode power amplifier is presented in this paper. First, the dynamic model of the shaker system is found and a high-performance current-controlled pulsewidth modulated inverter is designed and implemented. Then, a sophisticated acceleration control scheme being capable of waveform and magnitude regulation controls is proposed to lessen the undesired harmonic vibration caused by switching-mode driven power. In acceleration waveform control, the feedback controller is augmented with a feedforward controller and robust controller for obtaining excellent waveform tracking performance over a wide frequency range. As to the magnitude regulation control, the amplitude of the sinusoidal acceleration is accurately controlled to be equal to the setting value. Theoretical basis, practical consideration, and implementation of the proposed controllers are described in detail. Good current and acceleration control characteristics of the designed shaker are demonstrated by some measured results 相似文献