超视距宽带信号同步测量技术研究

发布时间：2018-01-22 20:31

本文关键词： 超视距步进频率信号同步测量蒸发波导　出处：《仪器仪表学报》2014年11期 　论文类型：期刊论文

【摘要】：本文提出了一种新颖的超视距条件下信道的宽带信号同步测量技术。首先在发射端和接收端各利用一台基带信号发生器产生相同频率的宽带步进频率信号。然后,通过两台锁定于同一颗卫星的GPS时钟频率参考源,输出极高稳定度的10 MHz信号作为基带信号发生器的外参考源,使得宽带信号的相位保持一致。接下来,利用GPS时钟频率参考源产生的秒脉冲信号作为触发信号,保证基带信号发生器和矢量网络分析仪同步发射和接收信号。通过对宽带信号的频域响应进行逆傅里叶变换,间接获得了信道的时域脉冲响应。实验在相距几十km的海面利用蒸发波导作为传输信道。通过对信道的衰落特性多径时延分布情况的观测与分析,该方法可获得200 MHz带宽信号的频域响应,比相同条件下时域测量的信号带宽提高10倍,等效的时域脉冲宽度达到5 ns,实验结果验证了技术的有效性。
[Abstract]:In this paper, a novel broadband signal synchronization measurement technique for over-the-horizon channel is proposed. Firstly, a baseband signal generator is used at the transmitter and receiver to generate the same frequency broadband step frequency signal. . Through two GPS clock frequency reference sources locked in the same satellite, 10 MHz signal with extremely high stability is output as the external reference source of the baseband signal generator. The phase of the wideband signal is consistent. Next, the second pulse signal generated by the GPS clock frequency reference source is used as the trigger signal. It ensures that the baseband signal generator and the vector network analyzer simultaneously transmit and receive the signal. The frequency domain response of the wideband signal is transformed by inverse Fourier transform. The time-domain pulse response of the channel is obtained indirectly. The evaporation waveguide is used as the transmission channel on the sea surface at a distance of several tens km. The multipath time-delay distribution of the channel fading characteristics is observed and analyzed. This method can obtain the frequency domain response of the 200 MHz bandwidth signal, which is 10 times higher than the signal bandwidth measured in the same time domain, and the equivalent time domain pulse width is 5 ns. The experimental results verify the effectiveness of the technique.
【作者单位】：西北工业大学无人机特种技术国家级重点实验室;中国电子科技集团第二十二研究所;
【基金】：国家自然科学基金(61201320,61371023,41175012)项目资助
【分类号】：TN919.34
【正文快照】： 1引言近些年来,随着无线通信数据传输速率不断提高,无线通信系统所使用的带宽也随之增加。由于受环境变化、地形起伏、气候多变等因素的影响,这使得无线信道中的多径传播、时延和衰落的变化十分复杂,也给宽带信号的传输带来了较大影响。信道测量是信道统计模型建立、模型输入

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