Journal of Electrical and Electronics Engineering (Oct 2019)
On The Identification of Low Probability of Intercept Radar Signals using Time-Frequency Signal Analysis and Processing
Abstract
Low probability of intercept (LPI) radar signals are gaining recognition in the field of electronic warfare (EW) due to their unique characteristics. This paper presents an alternative method of analyzing and identifying these LPI signals using Wigner-Ville distribution (WVD). The WVD is modified using the Hamming and Kaiser windows in order to mitigate the effect of the noise in the identification process. Thereafter interpulse and intrapulse analyses were carried out to estimate various parameters of the radar signals. The interpulse analysis was carried out using instantaneous power (IP) estimated from WVD while intrapulse analysis was carried out using instantaneous frequency (IF), also estimated from the WVD. Finally, a rule-based classifier was designed based on the parameters estimated from the previous analysis in order to identify the radar signals. Performance analysis was carried out using confusion matrices at carefully selected signal-to-noise ratios (SNRs). Also comparison analyses with previous methods are carried out. Results obtained showed that 95% identification accuracy is obtained at minimum SNR of 0dB for any of the radar signals considered. It was generally observed that the method developed in this paper performed better than all the reviewed methods. As such the proposed method can be deployed in the field of EW for radar signal identification.
