ABSTRACT
In this chapter, we introduce spread-spectrum systems. Spread-spectrum sig-
nals have several forms in direct sequence (DS), frequency hopping (FH), and
time hopping. Spread-spectrum systems originated in military applications
in order to 1) provide capability for anti-jamming, 2) have the low proba-
bility of interception, or 3) make multiple users sharing a common channel
possible (the so-called code-division multiple access (CDMA)). The nature of
the spreading system is its transmission bandwidth is much wider than the
signal bandwidth. Therefore, it can provide low probability of interception
(LPI), low probability of detection (LPD), and anti-jamming for transmission
systems.
