The FPGA Implementation Of 4FSK Modulation And Demodulation Of DMR System

Trunking Communication System is one of the most rapidly growing special mobile communication systems. It's usually used as a group mobile dispatching system for special mobile communication purpose. During the development of mobile communication technology, trunking system is transferring from analog system to digital system. DMR is the latest digital mobile communication system the ETSI is improving. As a new communication system, DMR is engaging more and more concentration from communication organizations and device providers. Firstly this paper introduces some key technologies of physical layer of DMR system, including 4FSK modulation and demodulation, synchronization, code and decode, burst formation, channel timing, etc. The theory of 4FSK modulation and demodulation is the focus in this paper. After the algorithm verification and simulation by MATLAB, the 4FSK modulation and demodulation are realized by using Verilog HDL based on the FPGA chip of Altera company. In addition, the realization of the FIR filter by DA algorithm is also the key point and the principle is also presented. Finally, the system simulation result of the 4FSK modulation and demodulation is completed by Modelsim. The programming and board-level verification is carried out as well.