A Study On The Search System Based On Satellite Overlap Communication Technique

Satellite search and rescue system is a significantly effective means for searching and rescuing. However, the satellite search and rescue system of China is not global coverage or all-weather service. This thesis focus on the search and rescue system based on satellite overlap communication technique. Such system can utilize the existing transparent transponder, and thus avoid the requirement of launching specific satellite. As long as there is a satellite over the distress target, such system can work effectively.The main research results of this paper are as follows:1. Based on studying satellite overlap communication technique, a search and rescue system based on satellite overlap communication is designed. According to the requirement of searching and rescuing, the system parameters such as the target satellite and carrier frequency are selected. The feasibility of such system is verified through link budget. Based on the link budget,a burst transmission scheme using M-ary spread spectrum is designed for the search and rescue signals. In the transmission scheme, the channel coding scheme is also designed. Simulation results show that the designed transmission scheme can satisfy the requirements of satellite search and rescue system.2.To correctly capture the burst signals of search and rescue, a frame header for synchronization is designed. Accordingly, a FFT-based method for capturing the frame header is proposed. Simulation results show that, the proposed method can effectively capture the frame header at very low signal-to-noise ratio(SNR).