Classification of signals

This presentation gives basic information about signals and its classification

1. Classification of signals Mrs.R.Chitra , Assistant Professor(SS), Department of ECE, Faculty of Engineering, Avinashilingam Institute for Home Science and Higher Education for Women, Coimbatore.

2. contents What is a signal? Types of signal Examples Illustration Formulae involved

3. Signal A signal is defined as a function of one or more variables which conveys information A signal is a physical quantity that varies with time in general or any other independent variable Examples: ECG signal Speech signal

4. Graphical representation

5. Classification of signals 1. Continuous time signal and Discrete time signal 2. Periodic signal and Aperiodic signal 3. Even signal and Odd signal 4. Deterministic and Random signal 5. Energy and Power signal

6. Continuous time signal It is defined at every instant of time t Its amplitude varies continuously with time x(t) Also known as analog signal Examples: Speech signal Atmospheric pressure Atmospheric temperature

7. Examples:

8. Discrete time signal It can be defined for discrete instants of time Its amplitude varies at every discrete value n It is obtained by sampling the continuous time signal Mathematical representation X(n)=x( nT )=x(t) Where n=integer Here n=constant integer T=sampling period

9. Examples:

10. Periodic signals A continuous time signal is periodic if x(t)=x( t+T ),T>0----------1 For all values of t A discrete time signal is said to be periodic if x(n)=x( n+N ) For all values of n

11. Aperiodic signals A continuous time signal is aperiodic if x(t) not equal to x( t+T ) For all values of t A discrete time signal is said to be periodic if x(n) not equal to x( n+N ) For all values of n

12. Examples: Aperiodic signal

13. Fundamental period It is the smallest positive value of T for which the equation 1 holds Periodicity, T=2 * pi * m/w Example: Sin2pit Here w =2pi

14. Even and odd signal A signal is even when X(-t )=x(t) They are symmetric Eg : cosine wave A signal is odd when X(-t)=-x(t) They are antisymmetric Eg : sine wave

15. Examples:

16. Deterministic and Random signals A signal whose nature can be determined is known as deterministic signal They can be predicted A signal whose nature can’t be determined is known as non-deterministic signal It is also known as stochastic signal They can’t be predicted

17. Examples:

18. Energy and Power signal A signal is an energy signal if 0<E<infinity and P=0 A signal is a power signal if 0<P<infinity and E=infinity

19. Formula:

20. Thank you