| China has a vast territory,complex geography,large population and diverse climate which is one of the countries most severely affected by natural disasters worldwide.When these emergencies and natural disasters occur,they often cause serious damage to the communication infrastructure,bring great challenges to the development of rescue and relief work,and seriously affect our social production,life and stability.The urgency and importance of emergency communication security work are becoming increasingly prominent.Generally speaking,in addition to meeting the requirements of time burst,location uncertainty and business urgency,emergency communication should also have the characteristics of miniaturized equipment,easy rapid deployment,simple operation and reasonable cost.The software defined radio has strong flexibility,openness and functional modularity,which is very conducive to the flexible reconfiguration of the communication system.It not only saves the cost,but also can well meet the upgrading and updating requirements of the wireless communication system,and provides an idea and direction for the research and design of the emergency communication network system.Through the investigation and analysis of the current development status of emergency communication technology,and combined with the status of software defined radio platform to carry out the research and design of this subject.The main work of this paper is as follows:At first,through the research and analysis of the development status and appliance requirements of the present emergency communication technology,and according to some characteristics of the software radio platform,we choose to design and implement the emergency communication network system based on the software radio platform.Second,it investigates and analyzes the more mature software radio platforms commonly used in the market,and compares and summarizes their strong points and weakness.According to the analysis,the more feasible and stable SDR platforms are OAI(Openair-interface)and srsLTE.Then we analyze the codes of physical layer(PHY)downlink(DL)and test their performance through experiments,and further compare their benefits,shortcomings and characteristics.Thirdly,according to the above analysis and experimental comparison,srsLTE platform and USRP B210 hardware platform are selected to build the emergency communication network system.And the design principle and implementation process of srsue end,srsenb end and srsepc end of srsLTE platform are described in detail.Finally,Huawei mobile phones are used to test the system,which can successfully connect and achieve smooth network. |
