A High Precision and Fast Frequency Measurement Method Based on Spectrum Segmentation for UWB Electronic Reconnaissance System

摘要

In this paper, in order to overcome the challenges of frequency measurement in electronic reconnaissance system, the principle of fast time-sharing reception is adopted for precise frequency estimation. The 20ms in each frequency band is resided, and the conversion of 2GHz to 18GHz RF signal to intermediate frequency signal can be completed within 200ms. The digital channelization module is used to realize the threshold detection and attenuation control of signal, and the Fourier transform with decimal is carried out for the detected signal. Based on Rife’s frequency-measuring algorithm, a frequency-searching algorithm based on the balance principle is proposed to optimize the Fourier transform function with decimals through Taylor series expansion and power series table lookup, which improves the frequency resolution and reduces the computation. At the same time, it it able to optimize the frequency search strategy, and the minimum value principle can be abandoned. It is efficient to find the coarse frequency search value by comparing the spectrum information corresponding to the minimum point, and turns out to be efficient to solve the problem of large frequency measurement deviation under the condition of low SNR. The theoretical simulation results show that this algorithm has higher instantaneous processing bandwidth, higher frequency measurement accuracy and stronger noise adaptability. It has good engineering application value and can provide potential effective support for electronic warfare systems.