A radio tranmission
modulation technique derived from
AM.
AM produces a
carrier frequency and two
sidebands. If you
suppress the carrier (saves power), you get
double sideband, abbreviated DSB. (The carrier is reinserted at the receiver). If you suppress (filter) both the carrier and one sideband, you get single sideband (SSB).
Depending on which sideband is suppressed, you may need to receive either the upper sideband (
USB) or the lower (
LSB).