设计一个采用 2ASK（OOK）调制的数字通信系统，给定载波频率为码元速率的2倍，产生二进制随机数据，并仿真其对应的 2ASK 调制波形，分析其频谱。所产生的调制波形加入不同信噪比的白噪声，再观察其波形和频谱变化。-Design of a use 2ASK (OOK) modulated digital communication system, a given carrier frequency is twice the symbol rate, to generate a random binary data, and simulate its corresponding 2ASK modulation waveform, the spectrum analysis. Modulated waveform generated by white noise with different noise ratio, and then observe its waveform and spectrum changes.