Support Vector-Based Unsupervised Learning Approaches for Radio Frequency Interference Detection

The presence of unwanted signals in the radio frequency (RF) spectrum, called RF interference (RFI), is a major drawback in wireless communication systems. The detection of REI has been dealt mainly with signal processing and supervising machine learning approaches. In this paper, we investigate two unsupervised machine learning alternatives for REI detection, the one-class support vector machine (SVM) and the support vector data description (SVDD) algorithm, which delimit the class boundaries of normal signals in high-dimensional space, and view REI contaminated signal as novelty, i.e., outsiders from unknown classes. Similar to the popular binary SVM classifier, these two algorithms can learn from a relatively small training set, and they use unsupervised training to learn from typically unbalanced RFI data sets without need for data augmentation techniques as in supervised training. The experimental results for detecting three types of RFI, using scaling features to a range as a standardization method, show that SVDD has a low computational complexity and an accuracy of 90.74 % versus 91.67 % for the One-class SVM.