A Research Of Anti-Jamming In Satellite Communication Based On OBP

Satellite communication has a wide coverage, the communication capacity, high transmission quality, convenient networking,and it is easy to achieve global seamless links.Generally speaking,satellite communication is an important means of communication on a global scale.Thus,satellite communication has become an important way in military field. It can be used in reconnaissance, control of military operations, tactical coordination, intelligence gathering, etc. So it is essential means to modern information warfare. Therefore, as a key component of communication system, the link between communication satellite and ground, must be the focus of enemy to disrupt. In consequence, communication satellite signal anti-jamming measures becomes a hot research in the process of communication development.The article discusses the on-board signal processing mode in broadband satellite communication system based on WCDMA technology, and also studies the anti-jamming performance for communication by OBP(on baseband processing). For this purpose, firstly, this paper studies the protocol of on-board signal processing on SA-WCDMA satellite system,simulates the rate conversion of signal, Hadamard matrix processing,quantization,Turbo product code,8PSKmodulation,etc,and analysis the performance of each modules. Secondly, the paper analysis the ground WCDMA PRACH channel signal format and the structure of U2 B link, combine the on-board processing modules to build the uplink signal chain of PRACH using MATLAB and observe the reception performance. The study also establish a variety of traditional interference models to analyze the effect of Hadamard matrix processing and signal dispersion. The simulation is designed to observe the effect of anti-jamming action under the addition of the interference in WCDMA. The result shows that the baseband signal processing does enhance the anti-jamming capability of SA-WCDMA satellite system.Subsequently, this paper innovatively uses the Carrier Interference to achieve the technology of anti-jamming. The way takes advantage of Zadoff-Chu sequence to express the single bit information and make multi-carrier modulation. The receiving end uses the multi-carrier signal and local Zadoff-Chu sequence to restore the original signal. The study gives the overall designing model, analysis the performance of interference and its robustness. Finally, the paper proposes a method of utilizing Compressed Sensing to achieve anti-jamming purpose. The method uses the similarity between structure of baseband signal processing and the rules of selecting observation matrix in multi-carrier communication. At the receiving end, we use OMP(Orthogonal Matching Pursuit) algorithm to reconstruct the original signal. The results shows that the structure can maintain high-quality signal transmission when majority of signal band is under serious interference.