13. What is Spread Spectrum
?
Spread Spectrum technology is a wideband radio frequency technique developed
by the military for use in reliable, secure, mission-critical communication systems. It
is designed to trade off bandwidth efficiency for reliability, integrity, and security. In
other words, more bandwidth is consumed than in the case of narrowband
transmission
,
but the trade off produces a signal that is, in effect, louder and thus
easier to detect, provided that the receiver knows the parameters of the
spread-spectrum signal being broadcast. If a receiver is not tuned to the right
frequency, a spread –spectrum signal looks like background noise. There are two
main alternatives, Direct Sequence Spread Spectrum (DSSS) and Frequency
Hopping Spread Spectrum (FHSS).
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