Research And Realization Of Digital Interphone Test Based On DPMR Protocol

DPMR (Digital Private Mobile Radio) system protocol is one of the latest professional digital mobile communication standards, which is put forward by European Telecommunications Standards Institute (ETSI). As a new generation of digital communication systems, DPMR supports a variety of services, a wide range of applications for commercial, professional and public safety users.In the research, production and maintenance process of digital interphone, the relevant tests must been done to ensure the reliability of the performance. Up to now, the western developed countries have already developed a complete test system based on DPMR communication protocol, but its price is very high and there are a lot of restrictions in terms of public safety. Since the research on professional digital mobile communications test is of later start, there is not a specialized instrument in China to test cluster communication systems.In such an environment, our topic is raised and our major target is to develop how to test the communication performance of no-center digital radio based on DPMR communication protocol. These results will provide certain references and guides for the development of products using this protocol in the future.First, this paper describes the current status of development and research of digital radio and main advantages of DPMR.Second, this paper introduces the main segments of the communication protocol including the setting and the communication of the data link layer signaling in the structure and function of various frame formats and values of the description. Moreover, a variety of channel access rules are also presented.Third, this paper analyzes the various channel codes in DPMR protocol such as CRC, hamming coding, interleaving, scrambling and implement of various frames. Meanwhile this paper provides the relied principles and algorithms for implementation process and the protocol implementation of various frames in DPMR.After that, it describes the design process of a FIR filter which is used in DPMR protocol and the simulation in Matlab and the details of the 4FSK modem technology used in DPMR protocol with generation method and a demodulation method.Finally, this paper gives the relevant hardware implementation, which includes the realization process of hardware platform with NIOS software and in which corresponding test results based on band signal can be checked.In summary this paper mainly focuses on the process of formation of a variety of frame agreements and discusses the specific algorithms of various key coding technologies in detail, as well as the filter design and 4FSK modulation and demodulation algorithms, which are tested on the platform built.