A novel method for LPI radar signal sorting in multipath channel

Signal sorting of low probability of interception (LPI) radar signals is extremely important in electronic support measurement (ESM) systems. Usually, there are multipath interferences in the intercepted signals, which result in the decrease of signal sorting performance of conventional methods. In this paper, we present a local ambiguity function (AF)-based signal sorting method for multipath fading environments. The singular vectors of the local AF are extracted as the signal feature which is robustness to the channel effects. Then, a multiclass classifier based on support vector machine (SVM) determines types of the received signals. Simulation results show that the proposed method has a high accurate rate for the recognition of twelve types of LPI radar signals in multipath channel, even at low signal to noise ratio (SNR).