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Abstract:In recent years, following the development of space commutation, space information has become a critical part in space information network and will play a very significant role in winning future information war. A space information network with characteristics such as complex structure, special communication requirement, long delay, dependence on remote maintenance, and fragile ecological environment contains enormous security risks. Therefore, ensuring space information network safety is important. Intrusion-detection model as an important part of a network security system becomes a hot issue in space network security. We propose an intrusion-detection method that integrates anomaly with misuse, which supports automatic updates from a remote ground, and design a distributed intrusion-detection model of space information network.

The existing multi-tone jamming suppression algorithms for direct sequence spread spectrum (DSSS) communications are confined to the high sampling rate. The compressive sensing (CS) was applied to solve the problem. Firstly, the DSSS signal and multi-tone jamming sparse dictionary was built, the multi-tone jamming suppression algorithm used in compressed domain was designed. Secondly, due to the difficulty in getting the prior information of the sparse degree of the jamming, the adaptive multi-tone jamming suppression algorithm was designed by setting the control threshold. The theoretical basis of the algorithm were analyzed, the effectiveness of the algorithm was verified by computer simulation. The results show that the algorithm could suppress the multi-tone jamming effectively, the performance don't change over the jamming intensity, jamming quantity and jamming position. This will provide an effective method for the reconstruction of the compressed DSSS signal in the condition of the multi-tone jamming.

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