基于FRFT的双二进制偏移载波信号捕获算法

为了解决传统算法无法实现高动态下双二进制偏移载波(Dual binary offset carrier modulation,DBOC)信号同步的问题，提出了一种离散多项式相位变换(Discrete Polynomial phase Transformation,DPT)与部分匹配滤波器(Partial Matched Filter,PMF)结合分数阶傅立叶变换(Fractional Fourier Transform,FRFT)的算法。该算法首先通过DPT-FFT方法得到的动态阶数判断接收信号是否需要降阶处理，如果信号带有二阶多普勒变化率，先对信号进行降一阶处理，然后用PMF-FRFT的方法进行捕获。如果信号没有二阶多普勒变化率，只带有一阶多普勒变化率，直接使用PMF-FRFT的方法进行捕获。由MATLAB仿真结果可知，该算法相比DPT-PMF-FFT算法捕获概率有近 9.5dB的提升，并且该算法有效缩短了捕获时间。所以该算法可以较好完成高动态下信号的捕获。 

FRFT-based Dual Binary Offset Carrier Signal Acquisition Algorithm

For the problem of the synchronization of Double Binary Offset Carrier(DBOC) signal can not be realized in high dynamict environment by raditional algorithm,a Discrete Polynomial phase Transformation(DPT) and a Partially Matched Filter(PMF) combines the algorithm of Fractional Fourier Transform(FRFT) are proposed.The algorithm first determines whether the received signal needs to be reduced in order by the dynamic order obtained by the DPT-FFT method,if the signal has a second-order Doppler rate of change,the signal is first degraded and then captured using the PMFFRFT method.If the signal does not have a second-order Doppler rate of change,only with a first-order Doppler rate of change,capture directly using the PMF-FRFT method.It can be seen from the simulation results of MATLAB that the algorithm has nearly 9.5 dB improved the acquisition probability compared with the DPT-PMF-FFT algorithm,and the algorithm effectively shortens the acquisition time.The algorithm can better capture the signal under high dynamics.