Automatic Modulation Classification Using Time-Frequency Features in a GNU Radio-Based Framework

International Journal of Electrical and Electronics Engineering
© 2026 by SSRG - IJEEE Journal
Volume 13 Issue 3
Year of Publication : 2026
Authors : Raman R, Deepa N Reddy, S.Vishali, Rama Krishna Prasadh H
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How to Cite?

Raman R, Deepa N Reddy, S.Vishali, Rama Krishna Prasadh H, "Automatic Modulation Classification Using Time-Frequency Features in a GNU Radio-Based Framework," SSRG International Journal of Electrical and Electronics Engineering, vol. 13,  no. 3, pp. 38-50, 2026. Crossref, https://doi.org/10.14445/23488379/IJEEE-V13I3P104

Abstract:

Automatic Modulation Classification (AMC) is one of the most crucial functions in the advanced wireless communication systems. Mainly, it is used in applications such as cognitive radio, dynamic spectrum access, and interference monitoring, where the knowledge of the transmitted signals is lacking. In the current work, we scrutinize an AMC framework with BPSK, QPSK, and 16-QAM as candidates for modulation under diverse Signal to Noise Ratio (SNR) conditions in detail. A synthetic dataset is produced by means of self-made GNU Radio flowgraphs with the addition of white Gaussian noise in order to mimic real-world wireless transmission situations. Time-frequency features are retrieved with the Short-Time Fourier Transform (STFT) and discrete wavelet transform, and three classical machine learning algorithms, Naive Bayes, Random Forest, and Support Vector Machine (SVM), are applied to classification. The framework is rated in terms of both classification accuracy and computational efficiency at varying SNR levels. The outcomes show that SVM coupled with wavelet features reaches the peak classification accuracy of 97.0% at 10 dB SNR, while the Naive Bayes classifier is the fastest in training time, and hence it can be deployed in real-time and resource-scarce applications. The findings indicate that combining lightweight machine learning methods with suitable time-frequency features can be an effective and efficient alternative to deep learning AMC frameworks in terms of computational cost.

Keywords:

Modulation Classification, Wavelet Transform, Short-Term Fourier transform, Machine learning, Signal to Noise Ratio.

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