QPSK

代码说明：

  QPSK 调制全称 Quadrature Phase Shift Keying，意为正交相移键控，是 一种数字调制方式。它的频带利用率高，且抗干扰性能强，已经成为现代通信 技术中一种十分重要的调制解调方(QPSK’s full name is Quadrature Phaseshift Keying which is a kind of digital modulation types. It has been widely used in wireless communications and has become very important in modern communication because of its high bandwidth efficiency and strong anti-interference performance)