Research Of DMR Repeating Model And Design Of Software In Basestation

With the development of mobile communication,mobile communication has developed to 4G and will comes into 5G.Private Mobile Radio stay in a special situation which will be changing from analogue communication to digital communication. Digital Special Wireless system can provide more clear voice,further cover,connectting faster and so on.At present,the mature technology of Digital Special Wireless system are TETRA system and i DEN system,but these two technologies may cost must.In 2005 ETSI proposed a new digital private mobile radio which named DMR standard.DMR standard have a effect on digital private mobile radio in middle-low-priced products, simple implementation, compatible with analog special wireless system equipment. In recent years, the DMR protocol standard has been more and more famous, at present the products which use DMR standard are in great demand in marketIn this paper, firstly I introduces the development of DMR in China.I analysis and compare a variety of digital interphone appearing on the market.DMR digital interphone is accepted by many company.Then a simple description of DMR air interface protocol is made.In this paper,I describes the frame format, signaling, channel, and communication with PSTN networks. For a small digital private mobile radio system which only have one base station, I discusses its performance, obtaining the the relationship between the traffic performance and the call drop rate,. Finally,I have a simulation on the 4 simplex channels and 2 duplex channels.The software design of base station is the key content. The analysis of the various of signaling in the base station process, the state transition of the call control layer, the conceptual design and the analysis of feasibility of the cache are done, finally I obtains the detailed processing of DMR protocol on the base station. Then over the Linux operating system, operate the designed software with 2 cases divided into simplex and duplex and analyzed the results. The voice can correctly repeating from the source to the destination and the voice is clear.Finally, this paper made a brief summary of the project of the tier 1. I introduces the work that done in the first stage.I introduces the keyboard, LCD display and write frequency software, and show the results.