Automatic modulation classification using convolutional neural network with features fusion of SPWVD and BJD

Automatic modulation classification (AMC) is becoming increasingly important in spectrum monitoring and cognitive radio. However, most existing modulation classification algorithms neglect the complementarities between different features and the importance of features fusion. To remedy these flaws, this paper presents a scheme of features fusion for AMC using convolutional neural network (CNN).The approach attempts to fuse different images and handcrafted features of signals to obtain more discriminating features. First, eight handcrafted features and different images features are both extracted. In the latter, signals are converted into two kinds of time-frequency images by smooth pseudo wigner-ville distribution (SPWVD) and Born-Jordan distribution (BJD), and a fine-tuned CNN model is utilized to extract image features. Second, the joint features are formed by combined of each of image and handcrafted features, and a multimodality fusion (MMF) model is applied to fuse the joint features to yield further improvement. Finally, simulation results reveal the superior performance of the proposed scheme. It is worth mentioning that the classification accuracy can reach 92.5\% with signal-to-noise ratio at -4dB.