{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

SP_I_P01_4p

# SP_I_P01_4p - Introduction to Signal Processing 1...

This preview shows pages 1–4. Sign up to view the full content.

Introduction to Signal Processing 1 Copyright © 2005-2009 – Hayder Radha I. Basic Signal and System Concepts A. Definition of a Signal Definition: A signal is a measure of some physical phenomenon, such as an electrical current, the temperature at an airport, etc. and it is a function of one or more variables. Introduction to Signal Processing 2 Copyright © 2005-2009 – Hayder Radha Most popular signals in electrical and computer engineering are functions of a single variable, which is usually time . A signal is usually a reference to the mathematical representation of the physical phenomenon under consideration. This physical phenomenon normally changes over time. Hence, we commonly express signals as functions of time: () x t , yt , ( ) it , vt ,…. Introduction to Signal Processing 3 Copyright © 2005-2009 – Hayder Radha Examples of Signals 1. Signals as functions of a single variable An example of a signal that is a function of a single variable is the voltage across an electric device such as a resistor, capacitor, or inductor: . Below is an example of a signal representing the voltage decay across a capacitance that is discharging its energy into a resistor starting at time zero: () ( ) exp , 0 t t =− . Introduction to Signal Processing 4 Copyright © 2005-2009 – Hayder Radha 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 t

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Introduction to Signal Processing 5 Copyright © 2005-2009 – Hayder Radha 2. Signals as functions of two variables A prominent example of a signal that is expressed as a function of two variables is an image (picture) signal. The two variables usually represent two-dimensional spatial variable. Introduction to Signal Processing 6 Copyright © 2005-2009 – Hayder Radha x y Introduction to Signal Processing 7 Copyright © 2005-2009 – Hayder Radha 3. Signals as functions of three variables A video signal is an example of a function of three variables, two spatial variables and a time variable. In this course we will mainly focus on signals that are functions of a single variable. Introduction to Signal Processing 8 Copyright © 2005-2009 – Hayder Radha B. Signal Properties and Classification of Signals A signal can be categorized and classified using several key properties. Below we outline these properties that lead to different types of signals.
Introduction to Signal Processing 9 Copyright © 2005-2009 – Hayder Radha 1. Continuous-Time and Discrete-Time Signals By considering a typical signal () x t that is a function of a single (time) variable t , one can classify a signal depending on the nature of this single variable (horizontal axis or domain ) under consideration. If the signal is a function of continuous time, then we have a continuous-time signal . In this case, the signal is defined over a continuum of time values. An example of a continuous-time signal is: Introduction to Signal Processing 1 0 Copyright © 2005-2009 – Hayder Radha () ( ) exp x tt =− . 0

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### Page1 / 20

SP_I_P01_4p - Introduction to Signal Processing 1...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online