The Stringent (Very Strict Conditions) frequency response requirements on the sideband filter in SSB –
SC modulation can be relaxed by allowing a part of the unwanted sideband (called as vestige) to appear in the o/p
of the modulator.
Due to this, the design of the sidebard filter is Simplified to a great extent. But the bandwith of the system
is increased slightly.
Explain VSS modulation? Mention the advantages and applications of VSB modulation.
In VSB, one sideband & a part of the other Sideband called as vestige is transmitted. So the bandwith
required for VSB transmission is somewhat higher than that of SSB modulation.
To generate a VSB signal, 1st we have to generate a OISB – SC Signal & then pass it through a sideband
filter as shown in figure. This filter, will pass the wanted sideband as it is along with a part of unwanted
Frequency – domain description of VSB waves :-
Fig (b) Spectrum of VSB modulated wave.
Fig shows the spectrum of a VSB modulated wave S(t) along with the message signal m(t).