An Evaluation Method of Electromagnetic Interference Based on a Fast S-Transform and Time–Frequency Space Model

Electromagnetic interference has a serious impact on the normal operation of electronic equipment. Evaluating the complexity degree of electromagnetic interference is a prerequisite for effective anti-interference. This article proposes a novel electromagnetic environment complexity evaluation algorithm based on the fast
S
-transform (FST) and time–frequency space model, which can extract three main characteristic parameters simultaneously. First, the equations for the time complexity, frequency complexity, and energy complexity are derived simultaneously by using the FST. Then, the computational methods and concepts of qualitative and quantitative evaluation degrees are introduced using the time–frequency space model. To overcome the 1-D limitations of the traditional method, the 3-D time–frequency space coincidence degree and root-mean-square are selected as two important evaluation indicators. Finally, combined with the time–frequency space model, we performed an electromagnetic interference experiment taking the radio frequency identification card as a test subject. The simulation and experimental results show the correctness and effectiveness of the proposed method.