Single Sideband Modulation

Cuthbert Nyack
Since the 2 sidebands in a DSB signal carry the same information, then one can go furthur in improving the efficiency of the transmission by transmitting only 1 sideband(upper or lower one can be used). The resulting signal is referred to as single sideband SSB.

The red curve below shows a SSB signal. It consists of a wave whose amplitude and frequency changes as the the amplitude and frequency of the modulating signal changes. Orange curve in applet shows the AM signal which results when the SSB signal is added to a carrier which is generated in the receiver. Changing the scrollbars show that the envelope of the AM is not much affected by the phase of the introduced carrier.

Changing the frequency of the carrier causes the frequency of the modulation to change but the general shape remains the same. Some distortion results from the use of only one sideband to produce the AM signal.



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COPYRIGHT © 1996 Cuthbert Nyack.