Researchment And Realization Of DMR Protocol

Public mobile communications and private network communication are two major application areas of mobile communications. The public mobile communication in China has been digitized, but private network communication is still at the simulation stage. European Telecommunications Standards Institute in 2005 has introduced two kinds of the civilian radio standards:DPMR (Digital Private Mobile Radio) and DMR (Digital Mobile Radio), which promoted developing of digital walkie-talkie. DMR uses TDMA technology to support duplex communication and data-speech transmission, so it has better prospect. However, DMR at home and abroad is still in its infancy. This article researched and implemented on the DMR protocol according simplified OSI layered model.First, the paper analyzed TDMA digital walkie-talkie development prospects and overall researched on DMR standard according to the simplified OSI layered model. And then it researched on frame structure, signaling system, call flow, modulation of physical layer and so on.Second, the paper designed and realized the channel codes arithmetic in DMR protocol, optimized some channel codes, simulated these channel codes under Matlab simulation tool, and the results showed that these channel codes optimized the BER performance.Finally, this paper presented and compared two implementations DMR protocol. And combined with previously studied, we realized voice communication of DMR protocol through AT commands.