The Research And Realization Of Modulation Technology And The Voice Transmission Based On The SB3500

Since its appearance, wireless communication technology has been closelyconcerned. In recent years, because communication technology develops quickly, theapplication of specific wireless communications products is loved by more and moreindustrial and commercial users. industrial and commercial users. With the increase ofthe number of users and the diversity of needs, the dedicated wireless communicationstechnology is gradually converted from analog cluster to digital cluster. Digital MobileRidio communication system which is a professional digital mobile communicationsstandard is formulated by ETSI in April2005. Because it is cheap and easy toimplement, the manufacturers have a strong interest in it. Firstly, the paper introducesthe key technologies of DMR baseband transmission system, mainly including errorcontrolling techniques, integer interpolation technique, the digital pulse shaping filtertechnology and frequency modulation technology, etc. Secondly, the hardware andsoftware development platforms of DMR terminal machine are recommended, at thesame time,4FSK modulation technique and the research and realization of the basebandvoice transmission are discussed,4FSK modulation algorithm mainly includes the studyand implementation of filtering algorithm, integer multiples interpolation algorithm andorthogonal modulation algorithm, while voice transmission focuses on transceivercontrolling, the framing and split frame. Finally, DMR double time slot physicalstructure is constructed, the baseband modulation module and the voice transmissionmodule are connected to debug, so that the system can achieve real-time and accuratedata exchange between the NODE2in SB3500and AMBE2000. In addition, I and othermembers of the project team completed the baseband and wireless transmissionperformance test.