A New Method for Recognizing Pulse Repetition Interval Modulation

In a dense modern electronic warfare environment, there are a lot of radar signals. The identification of these radar signals is the main task of the electronic support measures systems. Pulse repetition intervals of signals received from radars can have various PRI modulations and levels. In this paper, a new method of recognizing PRI modulation type and its levels is proposed for ESM systems. The proposed method is based not only on the properties of the biased autocorrelation function of the PRI sequences but also on the development of a hierarchical clustering method for both classifying PRI modulation types and clustering the PRI levels. The performance of the proposed method has also been evaluated in a simulation scenario.