WIRELESS TECHNOLOGY --- FREQUENCY HOPING RADIOS
Frequency hopping radio is wireless technology that allows
transmitting of radio signal by switching rapidly a carrier among various other
frequency channels through a pseudorandom sequence that is known to the
receiver and the transmitter.
It is utilized as a multiple
access method in the frequency-hopping code division multiple access (FH-CDMA) scheme.
The way in which radio
spectrum is currently allocated to different wireless technologies can lead to
gross inefficiencies. In some regions, for instance, the frequencies used by
cellphones can be desperately congested, while large swaths of the broadcast-television
spectrum stand idle.
One solution to that problem is the 15-year-old idea of “cognitive radio,” in which wireless devices would scan their environments for vacant frequencies and use these for transmissions. Different proposals for cognitive radio place different emphases on hardware and software, but the chief component of many hardware approaches is a bank of filters that can isolate any frequency in a wide band.
One solution to that problem is the 15-year-old idea of “cognitive radio,” in which wireless devices would scan their environments for vacant frequencies and use these for transmissions. Different proposals for cognitive radio place different emphases on hardware and software, but the chief component of many hardware approaches is a bank of filters that can isolate any frequency in a wide band.
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