Digital modem technology in the digital communication occupies a very important position, commonly used digital modulation are: frequency shift keying (FSK) and phase-shift keying (PSK), and so on.

• 数字调制解调技术在数字通信中占有非常重要的地位，常用的数字调制有：移频键控（FSK）和移相键控（PSK）等。