ARLA/CLUSTER: Quadrature Modulation: Sines and Cosines by Paul Goossens

[Pedro Ribeiro (CR7ABP)]

Quadrature techniques are being used increasingly often to generate and 
process radio signals. A supplementary benefit is that older modulation 
methods such as FM and AM can also be demodulated easily using this 
technique. It also helps eliminate some annoying properties of 
receivers, in particular suppression of image frequencies. Furthermore, 
a quadrature AM (QAM) signal can be used to transmit twice as much 
information as an AM signal with the same bandwidth. This is especially 
nice considering how much information is transmitted on wireless 
channels these days.
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Artigo completo: http://www.pcradiokits.it/IMG/pdf/070153-W.pdf

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Pedro Ribeiro
Indicativo: CR7ABP
QTH: São Francisco, Alcochete
GRID LOC: IM58MR
** Limitado a RX em Categ. 3 até 31/03/2012 **
( Decreto-Lei 53/2009, Art 8, 2a e Art 5, 3a )
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