Complex-Valued Convolution and Frequency Global Filter for Automatic Modulation Recognition

Abstract

Automatic modulation recognition (AMR) plays an important role in cognitive radio and dynamic spectrum access, which has been widely applied in military and civilian applications. Due to the breakthroughs in deep learning (DL), DL-based AMR methods are becoming extremely popular. However, most existing DL-based methods are unable to deal with complex format data, and learning the mappings from the time series or its transformed representation to the true modulation type directly is difficult. To address these difficulties, this letter presents a complex-valued convolution and frequency global filter unit (CGFU), and proposes a hybrid neural network, namely CGF-HNN, which can efficiently exploit features from different domains. We evaluate the recognition performance of the proposed model on two well-known datasets, i.e., RML2016.10a and RML2018.01a. Simulation results show that the proposed model outperforms the existing state-of-the-art models.