The invention provides an
electromagnetic signal automatic modulation identification method and
system during testing based on time-frequency fusion. The method comprises the steps of firstly constructing an
electromagnetic signal data set; secondly, optimizing a kernel function to realize time-frequency
feature modeling, and constructing a double-input path; constructing a deep neural network again, inputting the preprocessed
signal sample into a time-domain
branch for
processing, analyzing a time-frequency
spectrogram through the time-frequency
branch, and introducing a channel attention mechanism to realize
feature fusion; secondly, freezing a time-frequency
branch, only training a time-domain branch, outputting a
logit value from an input
signal through a neural network, and
smoothing logit distribution into probability distribution through a scaling variable; carrying out sample
slicing processing on an input
signal, and realizing convergence by fusing a prediction result; and finally, optimizing affine parameters of the batch normalization layer to complete identification of the
electromagnetic signal modulation category. According to the method, the recognition accuracy of the model in a complex
wireless environment is improved, so that the electromagnetic signal can still be stably and reliably recognized under the condition of low SNR (
Signal to
Noise Ratio).