D-2 Glossary of Terms Glossary of Terms
D-2 PN: 10580-00318 Rev. P S412E UG
AM : Amplitude Modulation (AM) uses amplitude variation in proportion to
the amplitude of the modulating signal, and is usually taken as DSB-LC
(Double-Sideband Large Carrier) for commercial broadcast
transmissions and DSB-SC (Double-Sideband Suppressed Carrier) for
multiplexed systems.
AMC : Adaptive Modulation and Coding (AMC) is an alternative link
adaptation method in 3G mobile wireless communication. AMC
provides the flexibility to match the modulation-coding scheme to the
average channel conditions for each user. With AMC, the power of the
transmitted signal is held constant over a frame interval, and the
modulation and coding format is changed to match the current received
signal quality or channel conditions.
Analog System : An Analog system uses an analog transmission method to send voice,
video and data-using analog signals, such as electricity or sound waves,
that are continuously variable rather than discreet units as in digital
transmissions. Mobile analog systems include AMPS, NMT and
ETACS.
Analog
Transmission : Analog Transmission refers to signals propagated through the medium
as continuously varying electromagnetic waves.
Antenna : Antenna is a device which radiates and/or receives radio signals,
including RF, microwave, and RADAR.
Antenna
beamwidth : Antenna beamwidth, also known as the half-power beamwidth, is the
angle of an antenna pattern or beam over which the relative power is at
or above 50% of the peak power.
Antenna Directivity : Antenna directivity, also known as antenna gain, is the relative gain of
the main beam of an antenna pattern to a reference antenna, usually an
isotropic or standard dipole. Antenna Directivity is the percentage of
radiated signal transmitted or received in a given direction related to
beamwidth.
Antenna Efficiency : Antenna Efficiency is the percentage of theoretical gain actually
realized from an antenna.
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