dsb

Amplitude modulation of a carrier wave normally results in two mirror-image sidebands. The signal components above the carrier frequency constitute the

upper sideband

(

USB

), and those below the carrier frequency constitute the

lower sideband

(

LSB

). In conventional AM transmission, the carrier and both sidebands are present, sometimes called

double sideband

amplitude modulation (

DSB-AM

).

载波的幅度调制，通常将导致两个镜像边带。以上的载波频率的信号分量构成的上边带（USB），和那些低于载波频率构成的下边带（LSB）。在传统的AM传输，载波和两个边带都存在，有时也被称为双边带调幅（DSB-AM）。