An reconstruction bidirectional recurrent neural network -based deinterleaving method for known radar signals in open-set scenarios

In electronic warfare, radar signal deinterleaving is a critical task. While many researchers have applied deep learning and utilised known radar classes to construct interleaved pulse sequences training sets for deinterleaving models, these models face challenges in distinguishing between known and unknown radar classes in open-set scenarios. To address this challenge, the authors propose a novel model, the Reconstruction Bidirectional Recurrent Neural Network (RBi-RNN). RBi-RNN utilises input reconstruction and employs a joint training strategy incorporating cross-entropy loss, reconstruction loss, and centre loss. These strategies aim to maximise inter-class latent representation distances while minimising intra-class disparities. By incorporating an open-set recognition method based on extreme value theory, RBi-RNN adapts to open-set scenarios. Simulation results demonstrate the superiority of RBi-RNN over conventional models in both closed-set and open-set scenarios. In open-set scenarios, it successfully discriminates between known and unknown radar signals within interleaved pulse sequences, deinterleaving known radar classes with high stability. The authors lay the foundation for future unsupervised deinterleaving methods designed specifically for unknown radar pulses.