The Design Of GSM-based CAPF Regional Communication Command System

Global system for mobile communications(GSM)is the first unified standard for mobile communication network in the world.Its emergence and development play an indispensable role for the interoperability of mobile users.After many years of development,it is regarded as a very outstanding communication system because of the matureness,stability,low economic cost,wide coverage.Communication command is an essential part in the daily life of the Chinese Armed Police Force(CAPF),whatever on duty training,sudden security and service support.For a long time,few improvements have been done for communication and command,thus making it in a relatively primitive and simple stage.Especially for the base course armies in remote mountainous areas,the fighting power is restricted due to the lack of effective command and communications support.Therefore,motivated by this consideration,the dissertation combines the communication needs for remote mountain areas,designs a communication and command system,and investigate the related key techniques,which is listed as follows:Firstly,we investigate the GSM communication protocol.In particular,we focus on the analysis of short message structure and the send-receive process.Moreover,we make the corresponding analysis for different message encoding schemes and use C++ to parser information.Experimental results show that the data stream can be accurately parsed out into text messages.Secondly,we study the localization problem in the GSM mobile communication network.Aimed to solve the low accuracy issue of time difference of arrival(TDOA)in non-line of sight(NLOS)environments,we analyze and propose an unscented Kalman filtering(UKF)based error suppression scheme.Simulation results demonstrate that when the proposed scheme applies to Chan positioning algorithm in the COST259 channel,it can achieve good positioning accuracy and outperforms better than classical TDOA algorithm.Finally,we design and complete the CAPF regional communication command system.The simple communication device achieves a rapid uplink and downlink information transmission as well as network equipment management;short message analysis program and protocol analyzer can extract the text information from short message communication in command terminals;the mobile devices localization,targeting and successful implementation on the map mark are also completed.Research results show that,GSM Application Communication Command work can improve work efficiency to a large extent,promote communication and command work force development.The establishment of communication command system can provide the desired practical functions in remote mountain areas and lay a solid foundation for the development of CAPF.