Signals and Systems

1.9 CLASSIFICATION OF DISCRETE TIME SIGNALS

Discrete time signals can be classified as follows:

• Even and odd signals
• Periodic and non-periodic signals
• Deterministic and random signals
• Energy signals and power signals
• Muitichannel and multidimensional signals

1.9.1 Even and Odd Signals

A discrete signal is said to be even or symmetric

 

x(n) = x(−n)     (1.55)

 

A discrete signal is said to be odd or asymmetric if

 

x(n) = −x(−n)     (1.56)

 

Figures (1.22) and (1.23) show the even and odd signals.

 

 

Fig. 1.22 Even signal

 

 

Fig. 1.23