Direct-sequence spread spectrum: Difference between revisions

Revision as of 02:02, 4 August 2005

Revision as of 17:07, 20 August 2005

Line 2:

# A [[system]] (a) for generating spread-spectrum transmissions by [[phase]]-modulating a [[sine wave]] [[pseudorandom]]ly with a continuous [[string]] of [[pseudonoise]] [[code]] symbols, each of duration much smaller than a [[bit]] and (b) that may be time-gated, where the transmitter is keyed periodically or randomly within a specified [[time]] interval.

# A [[signal]] structuring technique utilizing a [[digital]] code [[sequence]]([[PN Sequence]]) having a [[chip rate]] much higher than the [[information]] signal [[bit rate]]. Each information bit of a [[digital signal]] is transmitted as a pseudorandom sequence of chips.

Put simply, direct-sequence spread-spectrum transmissions multiply the data being transmitted by a "noise" signal. This noise signal is a pseudorandom sequence of <code>1</code> and <code>-1</code> values, at a frequency much higher than that of the original signal, thereby spreading the energy of the original signal into a much wider band.