Research And Implementation Of Emergency Communication System For Disaster Relief

With the continuous progress of science and technology,communication technology has entered a rapid development stage.The mature application of 4G technology,the rise of 5G technology and the development of satellite telephones,which are independently studied in China,have changed our lives and become an indispensable part.At the same time,the research direction of communication technology is also diversifying.Emergency communication is one of the most important research directions.The existing means of emergency communication include vehicle emergency communication,satellite communication,digital trunking communication and wireless trunking communication,but these communication methods can not achieve both cost and flexibility.In this thesis,UAV and long-distance communication are combined.Emergency rescue communication system in disaster area is studied and designed.Many-to-one long-distance voice communication is realized in the environment of no base station and multiple obstacles.Through the investigation and analysis of the current research status of emergency communication technology,combined with the development status of UAV,the research of this topic is carried out.By analyzing the functional requirements of the system,the overall design scheme of the disaster relief emergency communication system and the system framework composed of multiple transmitters,relays and receivers are given.The hardware design ideas of transmitter and receiver based on TMS320VC5509 A are elaborated in detail,including audio codec circuit,power conversion circuit,Lo Ra wireless communication circuit,etc.The hardware design ideas of relay based on STM32F103C8T6 are elaborated,including serial signal conversion circuit and power conversion circuit.In the software design part,the software programming environment is introduced,the communication protocol between transmitter and relay,and the data communication protocol between transmitter and receiver are formulated.The software design ideas of transmitter,relay and receiver are elaborated in detail,and the audio coding and decoding algorithm G.729A is studied and implemented.In the outdoor environment,appropriate verification scenarios are selected to simulate the environment of communication interruption between the disaster area and the outside world,and the emergency communication system of disaster area is tested systematically to verify the feasibility and validity of the theoretical research results in this thesis.The test results show that the system runs stably and the data transmission is accurate.Within the effective transmission range of 3km,the receiver can receive voice from different transmitters clearly and recognize the number of the transmitter.This thesis proposes a flexible solution for emergency communication,overcomes some difficulties caused by the damage of communication infrastructure and complex terrain,and provides effective guarantee for disaster relief.