Page 14 - Schaum's Outline of Theory and Problems of Signals and Systems

CHAP. 11 SIGNALS AND SYSTEMS

form
x(t) =x,(t) +ix2(t)
where x,( t) and x2( t) are real signals and j = m.

Note that in Eq. (I.l) t represents either a continuous or a discrete variable.

D. Deterministic and Random Signals:

Deterministic signals are those signals whose values are completely specified for any
given time. Thus, a deterministic signal can be modeled by a known function of time I.
Random signals are those signals that take random values at any given time and must be
characterized statistically. Random signals will not be discussed in this text.

E. Even and Odd Signals:
A signal x(t) or x[n] is referred to as an even signal if
x(-t) =x(r)

x[-n] =x[n]
A signal x(t) or x[n] is referred to as an odd signal if
x(-t) = -x(t)
x[-n] = -x[n]

Examples of even and odd signals are shown in Fig. 1-2.

(4 (4
Fig. 1-2 Examples of even signals (a and 6) and odd signals (c and dl.