信号与响应函数卷积的简单理解

部分内容来自：https://en.wikipedia.org/wiki/Convolution

 上图的英文描述（来自wiki）：

1. Express each function in terms of a dummy variable
2. Reflect one of the functions: →
3. Add a time-offset, t, which allows  to slide along the-axis.
4. Start t at −∞ and slide it all the way to +∞. Wherever the two functions intersect, find the integral of their product. In other words, compute a sliding, weighted-sum of function where the weighting function is 

The resulting waveform (not shown here) is the convolution of functions f and g.

If f (t) is a unit impulse, the result of this process is simply g(t). Formally: