Electromagnetic interference complexity evaluation method based on optimal adaptive S-transform time-frequency space model

For the S-transform in the electromagnetic environment assessment process there are problems such as the amplitude varies monotonically with frequency leading to imprecise extraction of energy occupancy assessment parameters. This paper proposes a method of electromagnetic interference complexity assessment based on the optimal adaptive S-transform (OAST) time-frequency space model. The flexible adjustment of the window width of the S-transform window function is achieved by introducing adaptive parameters, so as to suppress the large migration of the amplitude characteristics with the signal frequency. The OAST time-frequency spatial evaluation model is derived and established; the evaluation criteria of the complexity based on the OAST time-frequency spatial model are analyzed and determined, overcoming the limitations of the independent grading of the traditional electromagnetic interference complexity evaluation parameters. Simulation and experimental results show that OAST can accurately extract the time-frequency energy occupation parameters and the feature parameters in the time-frequency domain are more accurate; the OAST time-frequency spatial model can evaluate the signal complexity level more accurately, and the evaluation experiments verify the correctness of the proposed method in this paper.