IOSR Journal of Engineering (IOSRJEN) e-ISSN: 2250-3021, p-ISSN: 2278-8719 Vol. 3, Issue 10 (October. 2013), ||V1|| PP 53-59 www.iosrjen.org 53 | P a g e Identification of Highly Jittered Radar Emitters Signals based on Fuzzy Classification Yee Ming Chen, Chih-Min Lin, and Chi-Shun Hsueh 1 Dept. of Industrial Engineering and Management, Yuan Ze University , Chung-Li, Tao-Yuan, 320, Taiwan, R.O.C. 2,3 Dept. of Electrical Engineering, Yuan Ze University , Chung-Li, Tao-Yuan, 320, Taiwan, R.O.C. 2 Abstract: - Emitter signals identification is one of the key procedures in signal processing of Electronic Intelligence (ELINT). Jitter is an unintentional form of modulation that can have a wide variety of sources. Timing-related data errors will occur if jitter is beyond acceptable limits. Designers need a fast and easy way to obtain a complete characterization of clock jitter in microprocessor controlled. To enhance the ability of emitter identification (EID) to meet the requirement of modern ELINT, a novel identification approach for radar emitter signals based on type-2 fuzzy classifier is presented in this paper. This work discusses the impact of unknown jitter sampling on signal estimation. Based on the ELINT feature extraction of radar emitter signals, the type-2 fuzzy classifier is applied to identification of highly jittered radar emitters effectively. Experiment results shows that the approach can achieve high accurate classification even at higher error deviation level, and has good characteristics of identification. Keywords: - Signals identification, Fuzzy classifier, Electronic Intelligence I. INTRODUCTION Radar emitter signal identification is one of the key procedures of radar electronic intelligence (ELINT). In operational environments, it is important to know every radar emitter whether it is friend or foe, so that any counter measure could be applied in time. Number of homogenous pulse trains depends on radar transmitter power, sensitivity of ELINT equipment, distance to radar, antennas gain, methods of scanning and propagation conditions. Measurement information is included in so called pulse descriptor words (PDWs). Each PDW information depicting each particular pulse includes: radio frequency (RF), pulse amplitude (PA), pulse width (PW), pulse repetition interval (PRI), time of arrival (TOA), and direction-of-arrival (DOA) and so on. In the present days mostly, PDWs processing are virtually everywhere. The trend is toward more capable microprocessor-controlled systems that will run at faster and faster clock rates. As clock rates increase, characterization of timing accuracy and jitter becomes more important. Designers are finding an increased need to characterize jitter in order to achieve error-free design goals. Simply stated, jitter is just noise. The noise causes an uncertainty in the relative position of each clock cycle. Excessive clock jitter can limit performance in ELINT equipment. Because clock jitter is nothing more than the time variation between the edge of a clock signal and its ideal location in time, most engineers can intuitively relate to the basic definition of jitter. Period jitter is measured in the time domain and is expressed as either the rms or peak to peak of the time variation. Period jitter is defined as the variation in the time difference between the edge of a reference edge and the same edge of the clock uncertainty interval-valued clock cycles(Figure 1) . Figure 1. The clock uncertainty interval-valued clock cycles in ELINT modulation Jitter is an unintentional form of modulation that can have a wide variety of sources. Timing-related data errors will occur if jitter is beyond acceptable limits. Designers need a fast and easy way to obtain a complete characterization of jitter in microprocessor controlled ELINT. The impact of jitter can vary widely from one application to another. Because jitter takes many forms, it is important for the engineer to understand