§11 Introduction Any problems about signal analyses and processing may be thought of letting signals trough systems. f(t) h(t) y(t) o From f(t) and h(t), find y(t), Signal processing o From f(t)and y(t, find h(t, System design o From y(t h(t), find f(t), Signal reconstruction§1.1 Introduction Any problems about signal analyses and processing may be thought of letting signals trough systems. h(t) f(t) y(t) ❖From f(t) and h(t)，find y(t)， Signal processing ❖From f(t) and y(t) ，find h(t) ，System design ❖From y(t) and h(t)，find f(t) ， Signal reconstruction