4 Discrete LTI

Chapter 2Discrete LTIPrepared by Dr. Taha MAhdy

Discrete vs. continuousThe same concepts.a discrete time signal is one for which the time variable is defined only at specific discrete times. Such a signal can be realized by sampling a continuous time signal x(t) to form a collection or list of numbers x[n].

The difference between successive time steps is called the sampling interval.

Important Formulas

The unit impulse

Similar conceptsEven and odd functionsSketching System properties (linearity, time invariant, stability, causality, memory)Replace integral with summationEvery thing work as continuous

Discrete Linear Time-Invariant Systems

Compute the convolution

The result

Compute convolution

Block Diagram andDifference equations

Homework

Next lecture (Z transform)The following lecture, the midterm.