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Fully support this. --Paul 18:01, 2 October 2006 (UTC)
Both frequency hopping and direct sequence offer immunity to narrowband noise when compared to a conventional communication system. Therefore, I suggest removing the DS specific references from the last paragraph and adding links to other spread spectrum topics.
After a second reading, it might be better to remove the last paragraph and the com-stub tag. The former is about DS not PG and the later is a result of this being a fairly simple concept.
FHSS also offers immunity to narrowband interference, but not in the same way DSSS does, I guess. FHSS is instantaneously narrowband, so can still suffer bit errors during short periods of time, which is corrected in higher level) layers through error correcting codes and adaptive frequency hopping. DSSS is more "inherently" immune to narrowband interference through the processing gain, so I have to disagree with the above (unsigned) post. MrZap (talk) 10:40, 7 April 2010 (UTC)
Modulations
edit- FM - Frequency Hopped Spread Spectrum (FHSS) - is the ratio of the spread (or RF) bandwidth to the unspread (or baseband) bandwidth
- Direct-Sequence Spread Spectrum (DSSS) - ratio of chip rate over data bit rate in dB.
- Chirp Spread Spectrum (CSS) -ratio of sweep bandwidth over data bandwidth in dB
References
editProcessing Gain in Spread Spectrum Signals http://www.sss-mag.com/pdf/pgpap.pdf