vestigial side-band transmission

Vestigial side-band (VSB) transmission is a technique used in television broadcasting to efficiently use the available radio spectrum. When a television signal is modulated onto a carrier wave, it creates two identical bands of frequencies, known as upper and lower side bands. To conserve spectrum space, most of one side band is removed, while a small portion, or "vestige," of it is retained along with the complete other side band. This allows for a narrower bandwidth, simplifying receiver design compared to completely suppressing one side band. This method ensures that the complete picture and sound information is transmitted without wasting valuable broadcast spectrum space. The bandwidth of a modulated signal refers to the range of frequencies it occupies.12