The Design And Realization Of Wireless Real-time Voice Communication And Visual Personnel Management System

With the development of communication technology,the requirements of instant,convenient and lower-cost communication are increasing.The goal that people pursues is to communicate anytime,anywhere conveniently in real time.In modern communication systems,voice communication is one of the most important forms for human communication.In government agencies,business sector,hotel and catering industry,managers generally need to check staff attendance and communicate with them frequently.Based on wireless communication technology and computer software,the research and development of visual personnel management and wireless real-time intercom system in a small region,have an important value of application.Currently,there mainly exist two kinds of communication systems used in government agencies,business sector and other small areas.(1)Fixed telephone system:it has the properties of fixed installation location and immovable devices,and reduces the office efficiency to look up for numbers and dial.(2)Intercom system.:Firstly,traditional walkie-talkies adopt mode of analog communication,which has the disadvantages of weak anti-jamming performance and low voice quality.Although digital intercom technology is becoming mature,it's primarily analog in present market.Secondly,walkie-talkies usually adopt half-duplex communication,that is to say,the process of transmission and reception must be alternate,which causes the low real-time performance and operating inconvenience.Thirdly,intercom system generally works in broadcast mode,so it becomes difficult to ensure the confidentiality of communication.In addition,these two systems have a common flaw,that is,the caller can not know immediately whether the called party is online(in the communication area)and whether the other party receives this call promptly.So we need to solve the visualization problems of personnel management.Considering the problems existed in intercom system,the subject designs and implements a wireless real-time voice communication and visual personnel management system suitable for communications in star network with small areas,to achieve efficient,real-time,full-duplex,mobile voice communication and real-time personnel status and communication status display.The main researches that has completed are as follows:(1)This paper researched the wireless full-duplex transmission and time division duplex algorithm.By using low-power and low-cost RF chip,the system realized the time synchronization and time slot assignment of transmission and reception,and accomplished the two-way real-time transmission of data.(2)Through the analysis of speech processing and compression coding method,the paper researched and selected a voice processing chip based on the voice codec algorithm AMBE,and realized the whole process of speech signal.(3)According to the analysis of the causes of echo produced in real-time voice intercom systems and the study of the eliminating echo methods,the paper achieved echo cancellation during real-time speaking.(4)Using the Android platform,combined with the underlying voice processing and transmission module,this paper realized personnel visual management and convenient UI operations.