Deinterleaving Mixed Radar Pulse Sequences in Complex Electromagnetic Environments

With the increasing number of emitters and interference, coupled with the development of low probability of intercept techniques, the complexity of operational systems, and the integrated application of anti-jamming technologies, the pulse stream intercepted by reconnaissance receivers in modern electronic warfare exhibits characteristics such as high pulse missing rate, numerous spurious pulses, large observation noise, and complex pulse repetition interval (PRI) modulations. The previously described pulse stream is referred to as mixed radar pulse sequences in this article. Deinterleaving mixed radar pulse sequences is highly challenging due to the complexity of the electromagnetic environment. The existing methods suffer from issues such as insufficient consideration of complex electromagnetic environments and high computational complexity. This article introduces the concept of the PRI spectrum and analyzes its properties. Based on this representation, a PRI estimation algorithm that adapts to different PRI types is proposed. Additionally, an improvement to the pulse sequence retrieval algorithm based on directed acyclic graph (DAG) is proposed, enabling accurate separation of different pulse sequences. Simulation results show that the algorithm can successfully deinterleave of the mixed pulse sequences. When the jitter bound is 15%, the miss rate is 30%, and the spurious pulse count is 200 within 60 milliseconds, merr and PRism achieved 0.71% and 80.79%, respectively, demonstrating strong performance.