Suppressing the carrier in an amplitude modulated (AM) waveform produces
double sideband (DSB), which will increase the efficiency of the
transmission since only the sidebands are amplified. Some inefficiency still
remains, however, since the transmission bandwidth must still be twice
that of the message bandwidth due to the transmission of
both the upper and lower sidebands. These two sidebands are
redundant since all the necessary information can be conveyed by
only one sideband. When only one sideband is transmitted, the
transmission is called single-sideband suppressed carrier (SSBSC) or more commonly
SSB. When the upper sideband is transmitted the transmission is
called upper side band (USB) and when the lower sideband
is transmitted it is called LSB. This reduces the bandwidth
of the modulated wave by half and makes it equal
to that of the baseband signal. All of the transmitted
power then goes toward transmitting the baseband information.
Other topics in our resources on Communications Systems related to SSB include: