Representation of Signals

There are various methods to represent signals. Few of them are listed below :

1. Graphical representation
2. Tabular Form
3. Sequential Form
4. Functional Form

Graphical Representation

In case of graphical representation x[n] value will be plotted for each value of n(-∞ < n < ∞). It is easy to represent x[n] graphically if x[n] is of finite length.

Graphical Representation of a Discrete time signal x[n]

Tabular Representation

In this type of representation, a table is prepared for all values of x[n]. If the signal length increases it is tedious to prepare table for all values of n and x[n].

n	-2	-5	0	1	-3	4	2	3
X[n]	5	3	4	5	4	1	3	2

Sequential Representation

In this type of representation, a finite duration sequence with time origin (n=0). It is indicated by the symbol ↑ is represented as 

The arrow head represent that at 0 instant the amplitude of the signal is 3 while at -1 instant the signal has an amplitude of 2.

An infinite duration sequence can be represented as

Functional Representation

In case of functional representation, sequence x[n] is expressed in mathematical form such as