中文说明：此代码是密谋接收机工作特性曲线的简单能量检测法，当主信号是真正高斯信号和噪声是加性高斯白真实。在这里，阈值是可解析
English Description：
This code is to plot receiver operating characteristic curve for simple energy detection, when the primary signal is real Gaussian signal and noise is additive white real Gaussian. Here, the threshold is available analytically