一、基本定义及波形特性1.1持续时间和占用带宽的定义波形或信号(或噪声)过程的持续时间和占用带宽可以根据需要用不同的方法来下定义。目前常用的几种定义如下:A.按阈值定义(图1.1(a))时间函数的持续期可定义为这样的一个时间长度,即在这个时间长度之外,该函数值不超过指定电平。同样,时间函数的占用 I. Basic Definitions and Waveform Characteristics 1.1 Definition of Duration and Occupied Bandwidth The duration and occupied bandwidth of a waveform or signal (or noise) process can be defined in different ways as required. The most commonly used definitions are as follows: A. The definition of the threshold (Figure 1.1 (a)) The duration of the time function can be defined as the length of time beyond which the value of the function does not exceed the specified level . Again, time functions are occupied