基于MF-FRFT伪码捕获算法研究

发布时间：2018-07-25 17:33

【摘要】：针对高动态环境下接收机的接收信号含有较大多普勒频率及其变化率,传统捕获方法无法对多普勒频率变化率进行有效补偿的问题进行了研究,提出了一种基于分数阶傅里叶变换的捕获新方法。所提算法尝试采用匹配滤波器与分数阶傅里叶变换相结合的方法,利用在高动态环境下载波多普勒呈现近似线性调频信号的特点,寻找变换后峰值所在位置即可对多普勒频率和频率变化率进行有效估计,无须进行频域搜索,大大节省了捕获时间。理论分析和仿真验证表明,所提算法解决了传统方法在高动态环境下难以对信号多普勒变化率进行有效补偿的问题,尤其在低信噪比情况下,更好地提高了接收机捕获概率、缩短了捕获时间。
[Abstract]:The traditional acquisition method can not compensate the Doppler frequency change rate effectively because the receiver has large Doppler frequency and its change rate in high dynamic environment. A new acquisition method based on fractional Fourier transform is proposed. The proposed algorithm attempts to combine the matched filter with the fractional Fourier transform to make use of the characteristics of the carrier Doppler which presents the approximate linear frequency modulation signal under the high dynamic environment. The Doppler frequency and frequency change rate can be estimated effectively by finding the position where the peak value is located, and the acquisition time is saved greatly without frequency domain search. Theoretical analysis and simulation results show that the proposed algorithm solves the problem that the traditional method is difficult to compensate the Doppler rate of signal in high dynamic environment, especially in the case of low signal-to-noise ratio (SNR), the acquisition probability of the receiver is improved better. Shortened capture time.
【作者单位】：空军工程大学信息与导航学院;
【基金】：国家自然科学基金资助项目(61001111)
【分类号】：TN851

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