Design of FSK modulation and demodulation system based on FPGA

An FSK modem based on FPAG chip is proposed by the principle of FSK modulation and demodulation.The modulator module is designed by the keying method and the demodulator module is realized by the zero-crossing detection method in the system.The software programming is done by VHDL language in the Altera′s Cyclone series chip EP1C12Q240C6,then the appropriate timing simulation of the entire system is finished.The hardware testing shows that there is a certain delay but no difference between FSK demodulation signal waveform and modulation signal waveform to meet system design requirements,so the entire system has high reliability and portability.