Chapter 1 Continuous-time Signals and Systems
Chapter 1 Continuous-time Signals and Systems
§1 Introduction Any problems about signal analyses and processing may be thought of letting signals trough systems ft) 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 and 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
§1 Introduction There are so many different signals and systems that it is impossible to describe them one by one The best approach is to represent the signal as a combination of some kind of most simplest signals which will pass though the system and produce a response. Combine the responses of l simplest signals which is the system response of the original signal This is the basic method to study the signal nalyses and processing
§1.1 Introduction There are so many different signals and systems that it is impossible to describe them one by one The best approach is to represent the signal as a combination of some kind of most simplest signals which will pass though the system and produce a response. Combine the responses of all simplest signals, which is the system response of the original signal. This is the basic method to study the signal analyses and processing
81.2 Continue-time Signal ☆ All sig nals are thought of as a pattern of variations in time and represented as a time function f(t). %In the real-world any signal has a start Let the start as t=0 that means f(t)=0t0 Call the signal causal
§1.2 Continue-time Signal All signals are thought of as a pattern of variations in time and represented as a time function f(t). In the real-world, any signal has a start. Let the start as t=0 that means f(t) = 0 t<0 Call the signal causal
Typical signals and their representation o Unit Step u(t(in our textbook u(t) t>0 t<0 u(t-to) ●☆u( is basic causal signal., multiply which with any non-causal signal to get causal signal
Typical signals and their representation Unit Step u(t) (in our textbook µ(t)) { 1 0 0 0 ( ) > = < t t u t u(t) 1 0 t u(t- t0 ) 1 0 t t 0 u(t) is basic causal signal, multiply which with any non-causal signal to get causal signal