Research On Signal Analysis And Interference Mitigation Techniques Based On Intrinsic Time-scale Decomposition

With the development of the modern electronic counterwork, anti-jamming and jamming techniques become more and more important in this field. How to suppress various interferences effectively and how to interfere hostile part communication system are the important topics in communication counterwork field. Based on the intrinsic time-scale decomposition (ITD) algorithm, signal de-noising, narrowband interference mitigation in DSSS system, as well as hop-rate estimation and interferences for frequency-hopping system are discussed. The main contributions are as follows:1. A new de-noising algorithm based on ITD is proposed after analyzing the statistical characteristics of additional Gaussian white noise decomposed by ITD. The performance of this algorithm is simulated and the results show that the method is low in complexity and avoids wavelet base selection compared with de-noising algorithms based on EMD and wavelet.2. A novel algorithm for narrowband interference excision is presented based on ITD after analyzing the filter banks characteristics of white noise. This algorithm takes full advantage of low computational complexity, and mitigates both stationary and non-stationary narrowband interferences by time domain filtering directly.3. A new algorithm for estimating hop rate of frequency hopping signals based on ITD is proposed. This method makes the best of high time-frequency resolution of ITD and reduces noise effect due to the involved statistics conception. This algorithm achieves good results in low SNR. Jamming effects of several typical interferences to frequency-hopping system are simulated as well. According to simulation results, optimal interference mode is analyzed, which lays a theory basis for wartime communication counterwork.