A wavelet - based feature set for recognizing pulse repetition interval 1 modulation patterns

This paper presents a new feature set for the problem of recognizing pulse 10 repetition interval (PRI) modulation patterns. The recognition is based upon the features 11 extracted from the multiresolution decomposition of different types of PRI modulated 12 sequences. Special emphasis is placed on the recognition of jittered and stagger type PRI 13 sequences due to the fact that these types of PRI sequences appear predominantly in 14 modern electronic warfare environments for some specific mission requirements and 15 recognition of them are heavily based on histogram features. We test our method with a 16 broad range of PRI modulation parameters. Simulation results show that the proposed 17 feature set is highly robust and separate jittered, stagger and other modulation patterns very 18 well. Especially for stagger type of PRI sequences wavelet-based features outperform 19 conventional histogram-based features. Advantages of the proposed feature set along with 20 its robustness criteria are analyzed in detail. 21