Research on Anti-Jamming Technology of Chaotic Composite Short Range Detection System Based on Underdetermined Signal Separation and Spectral Analysis

The chaotic phase-modulated linear frequency modulation short-range detection system (CPLF-SrDS) is a new type of composite detection system. Compared with traditional methods, it benefits from the short-term randomness and long-term certainty of chaos and is more powerful in determining the distance. To design such a system, the key problem lies in robustly recovering the echo signal against externally suppressed interferences. Combining 4th-order cumulant and joint diagonalization, this paper first develops a new signal separation approach to realize an underdetermined separation of the echo signal and an interference signal from their mixture. Then, both bispectrum analysis and singular spectrum analysis are adapted to analyze the separated signals and extract their characteristic parameters. Furthermore, the GA-BP network is utilized to classify the echo and interference signals. Finally, the anti-interference analysis of this CPLF-SrDS is realized. The experimental results show the effectiveness of the proposed method in the presence of externally suppressed amplitude modulation (AM) interference and frequency modulation (FM) interference.