The Design And Realization Of Multi-Site Simulcast System Base Station Controller

Multi-site simulcast communication system is a system that several base stations'transmitters send the same information with the same frequency to receivers. It is seen as amelioration of general single-site and multi-site communication system. And it is also seen as supplement of trunking communication system. This thesis studies base station subsystem of simulcast communication system mostly, and design and realization of base station controller are emphasized. The base station controller can control relational equipment of the station and communication between simulcast base station and center base station, center base station and control center.Firstly, this thesis simply introduces background and actuality of simulcast communication system. It is applied widely inland and overseas. In succession, keystone and networking mode of simulcast communication system are introduced. The keystone includes three necessary qualifications, estimation and select of voice function of simulcast communication system. The following scheme and realization are based these qualifications. In this thesis, different frequency wireless link simulcast mode is selected as networking mode. Secondly, the thesis designs a kind of scheme of simulcast base station and center base station. And the requisite requirement and chip are introduced here, and the most important controller is ATMEGA128, the AVR microcontrollers of ATMEL corporation. The other roles are played by voice processing circuit, simulcast broadcasting station, data transmission broadcasting station, link transmitter-receiver and GPS module etc. And some theory is introduced here, which includes A/D conversion and correct code.Lastly, hardware circuit of base station control board is designed, which includes control module and voice processing module. And based the hardware, software flow of simulcast base station and center base station is designed. Protocol and flow between simulcast base station and center base station, center base station and control center are introduced in this section. Foremost, poll protocol is adopted between simulcast base station and center base station to accomplish call control. Then frame structure which used in protocol is explained...