FPGA implementation of 2FSK modulation system based on DDS

Digital modulation technique is the key technique of digital communication systems and it directly affects the performance and quality of digital communication systems. The traditional FSK (frequency shift keying) modulation methods are prone to sudden phase and the bandwidth utilization rate is not high. So 2FSK modulation system based on FPGA is proposed. In this paper a method with improved DDS (Direct Digital Synthesizer) technology is used to the system. The whole system is decided into digital modulation module and digital demodulation module. The implementation structure are given and the functional of modulation module and demodulation module are simulated. By the simulations, the function of each module can be realized. Because the less resources of FPGA are used, the system has the lower cost. At the same time, the design of modulation can be easier to transplant to other digital communication systems based on FPGA.The system also has the advantages of good portability and high applicability.