AIS System Of Gmsk Modulation And Demodulation

With the key technology of SOTDMA, Automatic Identification System (AIS) is used to communicate between AIS base station and ship, ship and ship, assist navigation in marine traffic management system with the intention of making marine navigation more safe. AIS system is composed with communication processing module, base band processing module, radio module and interface module. This paper is based on the base band processing design, as the bridge of communication processing module and receiving and sending module, base band module has taken charge of DSP of AIS protocol bottom.Based on the principle of GMSK, analyzing the form of GMSK modulation and demodulation, we have completed the system simulation of GMSK in the SYSTEMVIEW platform, at the same time, combined with hardware and software, we have realized modulation and demodulation of GMSK with the DSP chips TMS320VC549. It has stored key technology for our country, the hardware module not only embodied DSP's strong function and low cost, but also manifested the flexibility of software rewriting, it has a good stability to apply in AIS principle sample machine.With the kernel of base band module, this paper begined with the systematic configuration of AIS system, combined with the specific protocol, clearly clarified arithmetic simulation and realization. We certificated the credibility and stability of AIS system through the examination, the error is in the permissive range. Also it can make sure the safe of navigation, improve marine communication capability, accelerate the development of the navigation for our country.