Signals are functions 1.3 2003/07/26 22:49:13 GMT-5 2004/06/04 09:15:59.853 GMT-5 Richard G. Baraniuk richb@rice.edu Mariyah Poonawala mariyah@rice.edu Prashant Singh prash@ece.rice.edu A signal is a function that maps an independent variable into a dependent variable. The function f(x), for each value of x, produces the value f(x)

There are four ways to classify signals according to the values that the independent and dependent variables can take. Refer to the table below.

Quick Aside on Signal Notation Continuous Time signals are represented as f t where t . Discrete Time signals are represented as f n where n