Research on the Next Generation of Emergency Positioning Signal Design and Ground Stations Receive Processing Based on GNSS

As typical representative of the emergency research and rescue signal in the field of Life Safety and Emergency Service, both the 2nd generation COSPAS-SARSAT beacon and the BeiDou System (BDS) locating report (or named RDSS) signal have been practiced for more than 20 years. These two systems with emergency positioning signals played significant social value and economic benefits, but also gradually exposed some issues, such as the high-power consumption for user terminal, low reliability and so on. The performance improvement plans of the two emergency service systems have been put on the agenda respectively, including the signal structure and the system architecture. Based on the next generation of satellite-based emergency positioning and reporting system, this paper presented the design of a highly reliable and low-power user signal/distress beacon system, as well as ground station processing methods. Firstly, the characteristics of the system frame and signal structure for the existing two kinds of emergency positioning system are introduced. Then, further discussions on the key element and corresponding scheme of the next generation emergency location signal, among the aspects of spreading sequence, channel encoding, frame structure, message arrangement, are expanded. At the same time, in order to minimize the power consumption of the user terminal and make full use of the uplink multi-coverage of the satellite-based positioning report system, a ground station diversity receiving user emergency positioning signal/distress beacon processing method is proposed. The ultimate purpose of this research is to improve the terminal power consumption, single detection probability and other key indicators of the next generation of emergency search and rescue application, to 2 W consumption, which is 5 W of the current user terminal supported by the two systems.