The frequency shift keying modulation is widely used in hf digital communication 移频键控是短波数字通信中常用的一种调制方式。
After researching on the atmospheric transmission characteristic and light source characteristic , a modulation system based on 2fsk has been developed 通过对大气传输特性、光源发光特性的研究,研制出一套基于二进制移频键控( 2fsk )方法的调制系统。