Editing Amplitude modulation (section)

===Single-sideband===
In 1915, [[John Renshaw Carson]] formulated the first mathematical description of amplitude modulation, showing that a signal and carrier frequency combined in a nonlinear device creates a sideband on both sides of the carrier frequency. Passing the modulated signal through another nonlinear device can extract the original baseband signal.<ref name="Bray" /> His analysis also showed that only one sideband was necessary to transmit the audio signal, and Carson patented [[single-sideband modulation]] (SSB) on 1 December 1915.<ref name="Bray" /> This advanced variant of amplitude modulation was adopted by AT&T for [[longwave]] transatlantic telephone service beginning 7 January 1927. After WW-II, it was developed for military aircraft communication.