Radar signal sorting identification method and radar signal sorting identification device based on fractional order Fourier transformation

Abstract

The invention belongs to the technical field of radar signal identification, and relates to a radar signal sorting identification method and a radar signal sorting identification device based on fractional order Fourier transformation. The method comprises the following steps: acquiring each radar signal fractional order domain oscillogram through fractional order Fourier transformation; respectively performing normalization processing for the oscillogram, and constructing a joint feature parameter set; and performing sorting identification for feature vectors in the joint feature parameter set through a support vector machine sorter. According to the method and the device provided by the invention, based on difference of different signals in a fractional order domain waveform, multiple groups of symmetrical Holder coefficient values are extracted to form a joint feature vector, and automatic sorting identification for the radar signals is realized; the method and the device have relatively better intra-class aggregation degree and relatively higher anti-noise performance, can more completely express time-frequency features of a signal fractional order, and have certain applicationforeground; moreover, a simulation experiment result shows that overall average identification success rate for six types of radar signals is superior to 96.5% when signal-to-noise ratio is greater than 4dB, and the overall average identification success rate for six types of radar signals is superior to 84.8% when the signal-to-noise ratio is 0dB; and the method and the device also have better identification effect on complex modulation signals.

Description

technical field [0001] The invention belongs to the technical field of radar signal recognition, in particular to a radar signal sorting and recognition method and device based on fractional Fourier transform. Background technique [0002] Radar signal sorting and identification is an important part of electronic reconnaissance and support. With the development of modern radar technology, signal modulation methods are diverse, making it difficult for traditional sorting and recognition methods based on Pulse Descriptor Word (PDW) to meet the needs of signal recognition. Therefore, the analysis and mining of radar signal pulse characteristics It has gradually become a research hotspot. In recent years, domestic and foreign scholars have done a lot of work on radar signal intrapulse feature extraction, and proposed a variety of analysis methods, such as time-frequency analysis method, fuzzy function method, high-order statistics method, etc. However, these methods are easily...

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Problems solved by technology

Based on the characteristics of the FRFT modulus changing with the order and the waveform of the FRFT when the order is 1, the modulation characteristics identification of the chirp signal, frequency-coded signal and phase-coded signal is completed, but the signal types identified by this method are limited; The similarity coefficient and vergence characteristics of the order FRFT, and further extract the order value and kurtosis corresponding to the peak value of the curve, so as to construct a set of joint feature vectors for the sorting and identification of the three radar signals. This method is sensitive to noise. The recognition performance is not good enough under low signal-to-noise ratio; by studying the energy peak distribution characteristics of linear frequency modulation signal, symmetrical triangular frequency modulation continuous wave signal and polyphase coded signal in the fractional domain, a low interception radar signal based on FRFT is proposed Modulation identification method, the process of this method is relatively complicated, and it cannot effectively deal with radar signals of complex modulation types

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