Research On Measurement Methods Of Signal Parameters For Optoelectronic Cooperative Spectrum Analyse System

Signal parameter measurement is an important part of electronic reconnaissance.Along with the increase of the signal frequency and bandwidth in the radar and communication systems,measuring the parameters of high-frequency and large-bandwidth signals quickly and effectively has been regarded as major research concerns.Traditional signal parameter measurement approaches are generally based on digital signal processing,however,the reliability and efficiency would be sharply reduced when the high-frequency,high-density and large-bandwidth signals are applied due to the limitation of sampling and processing capability of existing digital processors,which cannot satisfy the future development.In the interest of solving these problems,the approach based on the optronic processing is proposed to accomplish the frequency domain calculation in optical domain combined with the digital processing to estimate the signal parameters.The novel approach takes advantages of high computational efficiency of microwave photonics and flexibility of digital processing,which enables fast and accurate parameter measurement in the case of high-frequency and large-bandwidth signals.Based on the discussion above,this dissertation mainly introduces the parameter measurement approach with optical Fourier transform.Compared with traditional signal processing approached,the Fourier transform designed in this dissertation is estimated from the optical system which make the usage of more complex and effective parameter measurement approaches possible.The main research contents of this dissertation are listed as follows.First,this dissertation takes advantage of the auto-correlation,short-time Fourier transform,interpolation and other instantaneous frequency measurement approaches to estimate the instantaneous frequency of the signals,thus estimating the frequency parameters of the three types of signals.Furthermore,a novel interpolation algorithm for sinusoidal signals is proposed which is closed to CRLB at a lower SNR.Second,in the cases of wideband characteristics of the chirp signal spectrum,two algorithms for estimating the chirp signal parameters based on MDCFT are proposed,which improves the measurement accuracy of the algorithm.Third,this dissertation analyzes the two-dimensional Fourier transform in the optical domain to estimate the signals time-frequency transform results through the optical domain transform results.With the help of PCA-SVM method and time-frequency images,the signal type and time parameter recognition are accomplished as well.