Design And Implementation Of Instant Messaging Terminal Based On Beidou System

Beidou satellite navigation system has short message communication capabilities,which covers a wide range with high security,and it will provide the worldwide service in 2020,it can solve the limitation of limited range of mobile cellular communication.However,due to problems such as frequency of SIM cardtransmission,Beidou short message communication is prolonged and the amount of information is small,in bad weather or environment,the input of Beidou text information will become difficult and the identity of the sender cannot be identified.Recently,the emergence of Beidou multi-card technology and low bit rate voice compression technology has made it possible to solve the above problems.Based on this,this paper combines Android technology to design and implement speech transmission for Beidou communication terminal,improves the Beidou communications volume,realizes Beidou Communication's portability and instantization and promotes the development and popularization of Compass Communications with the Beidou communications system unchanged.,the main contents are as follows:1.The feasibility of the paper is analyzed.It is clear that the key point of the paper is to increase the amount of communication information and deal with the contradiction between the communication bandwidth and the large amount of voice and picture data when Beidou communication bandwidth is constant.It is mainly solved from 4 aspects:The first is to improve the Beidou communication protocol,the effective information content of the protocol for a reasonable division and design,maximize the use of the Beidou communication bandwidth.The second is to optimize the communication process,divide the information into subpackage,set reasonable waiting time,and resend the lost packet.The third is to select the appropriate compression method,for voice,we adopt 600bps low voice codec software package,for image,we first use the size compression,and then use the libjpeg library method to further compress.The fourth is to adopt Beidou multicard technology in hardware,multiple SIM cards are polled,and data transmission is increased in unit time.The test proves that the above research and implementation can effectively increase the information amount of the Beidou communication.2.This paper selects the Beidou multi-card module,WiFi communication module,and Android communication terminal,using the Android Studio as a development tool to design and implement the Beidou Xuntong computer application(short for App).Software development is mainly divided into five major parts.The first part implements an effective connection between the Android communication terminal and the WiFi communication module,and tests the connectivity with the Beidou multi-card module.The second part completes the processing of sending,receiving and storing of communication information,and realizes packet processing of communication information.The third part realizes group user information viewing,selection and information sending and receiving display functions.The fourth part completes the setting function to obtain the Beidou main and auxiliary card information,and can perform self-test.The fifth part realizes the functions of Beidou satellite map positioning,Beidou satellite state diagram display,and the management of the walking positioning path.After extensive field testing,the app combined with hardware terminals can run effectively,satisfies instant messaging,enabling miniaturization of the terminal and portability of the communication.