基于分段FFT的脉冲伪卫星信号捕获方法

Pulsed Pseudolite Signal Acquisition Using Segmented FFT

建立了脉冲伪卫星信号捕获模型,并针对传统的饱和接收方法无法适应脉冲伪卫星组网应用下信号接收的问题,提出一种基于分段快速傅里叶变换(FFT)的脉冲信号捕获方法.该方法是一种串并行结合的捕获方法,既保证了捕获概率,又能极大地降低捕获时间.对分段FFT捕获方法和串行捕获方法的捕获时间进行了比较,研究了FFT方法在不同分段策略下的捕获性能,并针对脉冲截断问题提出了脉冲截断检测算法和分段调整方法.仿真验证了该方法的有效性.

For pulsed pseudolite signal acquisition, the traditional method is saturated receiving. But in pseudolite network application, this method does not meet well the demands. This paper proposes a new pulsed signal acquisition method using segmented fast Fourier transform（FFT）. The paper presents the pulsed pseudolite signal acquisition model, and analyzes the key performance of this method： acquisition time and acquisition probability. It focuses on the segmentation and the pulse truncation in the segmented FFT acquisition method. Software simulation indicates that short segment length and pulse truncation detecting algorithm can effectively improve the performance of FFT pulse acquisition.