What is signal & systems?
What is Signal? Signal is a time varying physical phenomenon which is intended to convey information. OR Signal is a function of time. OR Signal is a function of one or more independent variables, which contain some information. Example: voice signal, video signal, signals on telephone wires etc. Note: Noise is also a signal, but the information conveyed by noise is unwanted hence it is considered as undesirable. What is System? System is a device or combination of devices, which can operate on signals and produces corresponding response. Input to a system is called as excitation and output from it is called as response. For one or more inputs, the system can have one or more outputs. Example: Communication System