Dual Signal Fast Frequency Measurement Technology And Fpga Implementation

Based on data rate conversion technology, wideband digital EW receiver is able to achieve high intercept probability, high sensibility and the ability of approximately real-time signal processing. Data rate conversion technology for signal is one of the key technologies of wideband digital reconnoitering receiver. It is the feasible scheme to resolve the rate gap between the front end data flow of high speed Analog Digital Converter (ADC) sampling and the back end Digital Signal Processor (DSP) processing. Frequency estimation technology and bandpass filtering, which are named as wideband digital downconversion technology, are the key technologies to realize data rate conversion system. In this dissertation, the data rate conversion technology is studied and validated. High speed and accuracy dual signal frequency estimation algorithms are researched, as well as the implementation of the experimental system. The main work of the dissertation is as follows.(1) Signal characteristics under modern electronic reconnaissance environment is analyzed. It's pointed out that wideband digital receiver must satisfy wide monitoring band, pipeline operation and almost real-time response. A frequency guiding digital receiver is given. The key technology, fast frequency estimation and high effectual data rate conversion, is introduced briefly.(2) The FFT technology applied to frequency estimation algorithm is studied. Comparing with some kinds of FFT system-on-chip, FPGA is the best choice to design FFT module, which is to fulfill real-time processing request.(3) The conventional interpolated DFT algorithms are analyzed. A new method, which estimates frequency with high precision and fast rate compared with the mentioned methods for the real single tone based on DFT, is presented. The method, which only needs three real DFT coefficients, is at low computation and of high precision and fast frequency estimation.(4) A method, realizing the fast frequency measurement for dual sinusoidal signals basing on DFT and autocorrelation theory, is proposed. Firstly, one frequency and its amplitude are measured by DFT, with which to demodulate the signals and eliminate the...