Modulation scheme: Difference between revisions

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The [[Modulator]] converts an input signal into a form suitable for RF transmission. The [[Demodulator]] recovers the original signal. Since the RF signal is a based sine wave oscillating around the transmission frequency, the [[Modulator]] has to modulate this sine wave in a way so that all information is transmitted and well-recoverable but only as little [[Bandwidth]] as possible is allocated.
The [[Modulator]] converts an input signal into a form suitable for RF transmission. The [[Demodulator]] recovers the original signal. Since the RF signal is a based sine wave oscillating around the transmission frequency, the [[Modulator]] has to modulate this sine wave in a way so that all information is transmitted and well-recoverable but only as little [[Bandwidth]] as allowed is allocated.


The more the Modulation Scheme modifies the original sine wave the more the [[Frequency]] of the RF sine wave will vary -- the higher the [[Bandwidth]] will be.
The more the Modulation Scheme modifies the original sine wave the more the [[Frequency]] of the RF sine wave will vary -- the higher the [[Bandwidth]] will be.

Revision as of 19:22, 23 September 2004

The Modulator converts an input signal into a form suitable for RF transmission. The Demodulator recovers the original signal. Since the RF signal is a based sine wave oscillating around the transmission frequency, the Modulator has to modulate this sine wave in a way so that all information is transmitted and well-recoverable but only as little Bandwidth as allowed is allocated.

The more the Modulation Scheme modifies the original sine wave the more the Frequency of the RF sine wave will vary -- the higher the Bandwidth will be.


Analog Modulation Schemes
Shortform Name
AM Amplitude Modulation
FM Frequency Modulation


Digital Modulation Schemes
Shortform Name
BPSK Binary Phase Shift Keying
QPSK Quadrature Phase Shift Keying
QAM-16 16-state Quadrature Amplitude Modulation
QAM-32 32-state Quadrature Amplitude Modulation
QAM-64 64-state Quadrature Amplitude Modulation
QAM-128 128-state Quadrature Amplitude Modulation
QAM-256 256-state Quadrature Amplitude Modulation
8VSB 8-state Vestigial Side Band Modulation