应用于高动态接收机的分数阶傅里叶变换实现

摘要

For the problem that traditional FFT can't accumulate coherently under high-dynamic environment during a long-time period, and in order to track high-dynamic signal more efficiently, we use the feature of FrFT that its instantaneous frequency varies with time, to compensate Doppler frequency and Doppler frequency rate in the high-dynamic receiver. Closed-form algorithm is used to realize FrFT and design the tracking loop of high-dynamic receiver. Through one-dimension and two-dimension simulation based on Matlab, calculating Doppler frequency and Doppler frequency rate, and compare measurement value with the real value. The simulation proves that this tracking loop improve the tracking performance and the ability of anti-interference of the high-dynamic receiver.%针对传统的FFT在高动态环境下难以长时间对高动态信号进行相干累积的难题，以及为了达到对高动态信号进行更有效跟踪的目的，利用FrFT运算瞬时频率随时间呈线性变化的性质，将其应用到高动态接收机中去，对多普勒频率和多普勒频率变化率同时进行补偿。运用基于Closed－form算法实现FrFT运算，并设计高动态接收机信号跟踪环模块，通过基于matlab的一、二维搜索仿真，根据测量得到的结果计算多普勒频率和多普勒频率变化率，将测量值与真实值相比较。仿真证明该跟踪环提高了高动态接收机的跟踪性能和抗干扰能力。