说明：  本文件进行了数字基带调制系统的simulink反正，采用的是滚降升余弦滤波器，全套系统仿真效果良好，模块化，信号眼图良好
(In this paper, the Simulink of the digital baseband modulation system is carried out, and the roll down and rise cosine filter is adopted. The whole system has good simulation effect, modularization and good signal eye diagram)