Representation of

Signals

Today’s Outline Signal Types of Signal Signal Representation Elementary signals

What is signal?

Signal is a function that conveys information about the behavior or attributes of some phenomenon.

Types of signalTwo main types of signals encountered in

practice. Analog signal Digital Signal

Representation of Different Signals

• Periodic & Aperiodic Signal• Continuous & Discrete Signal• Orthogonal Signal• Even & Odd signal• Power & Energy Signal

Periodic signal Completes a pattern within a

measurable time frame, called a period Repeats that pattern over identical

subsequent periods. 

Periodic signal

Aperiodic SignalA signal that does not repeats its pattern

over aperiod is called aperiodic signal or non

periodic

Aperiodic Signal

Continuous Signal Time is a continuum. The function's domain is an uncountable

set. The function itself need not be continuous.

Continuous Signal

Discrete Signal Discrete-time signal is not a function of a

continuous argument. Obtained by sampling from a continuous-time

signal.

Discrete Signal

A signal is referred to as an even if it is identical to its time-reversed counterparts; x(t) = x(-t).

Even signals are symmetric around vertical axis.

Even Signal

Even Signal

Odd Signal A signal is odd if x(t) = -x(-t).  An odd signal must be 0 at t=0, in other

words, odd signal passes the origin.

Odd Signal

Power signalA power signal is a signal that has finite power for each point in time.

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Energy Signal An energy signal has a finite energy. A signal in energy signal if and only if the

condition(0 < E < ∞) is fulfilled.

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Orthogonal Signals Each component signal has no relationship

with others.   Orthogonal signal is denoted as φ(t). 

 

Elementary Signals• Unit step function• Ramp function

Unit step function

Ramp function

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