The Design Of AIS Baseband Data Processing Chip Based On FPGA

Nowadays, with the vigorous development of shipping industry, the safety of navigation is becoming more and more important, which requires high liability and stability of communication equipments. Automatic Identification System aka AIS transfers static, dynamic and navigation information in the VHF radio coverage range works for ships tracking and monitoring, which has improven the safety of navigation.AIS system includes shore base stations and ship stations. The object of this essay is about ship station system, which consists of antenna, the RF analog part and the AIS digital base band signal core processing chips etc. The AIS digital baseband signal processing chip majorly implements the functions of data transfering based HDLC protocol codec, and GMSK modulating and demodulating of the information through the physical communication link, and other functions. This research is the core part of the AIS system. This study-design is based on ISE12.3development platform and Verilog lauguage.This subject includes three parts.The first part is based on HDLC communication protocol, using state machine to achieve the AIS data transfering format codec. The second part is based on ITU-R M.1371-4, accomplished AIS data encoding using NRZI waveform, after the implement of the HDLC protocol, the data is handled through NRZI encoding. The third part is based on the principle of GMSK modulation and demodulation, which achieves the VDL information transmission, with the method of non-coherent demodulation during the demodulating process. The above three parts are divided, programed and synthesized in ISE12.3, and are simulated by Modelsim6.5.The subject is one of the key parts of the863sub-topic "GSOS System Terminal Equipment" project, which has been applied in this project.