Single-sideband modulation

Single-sideband modulation is an amplitude-modulation method that transmits one sideband while suppressing the carrier and the other sideband, conserving bandwidth and transmitter power.

Amplitude modulation: A modulation family in which a carrier’s amplitude varies with an information signal. Single-sideband modulation is a bandwidth-saving form of amplitude modulation.
Amateur radio: A radio service in which licensed operators communicate and experiment without commercial purposes. Single-sideband voice is a standard mode for long-distance amateur communication.
Double-sideband suppressed-carrier modulation: Amplitude modulation that transmits both sidebands while suppressing the carrier. It suppresses the carrier like single-sideband, but occupies twice the message bandwidth.
Frequency spectrum: A representation of a signal’s components by frequency and amplitude or power. The spectrum makes the carrier and the two sidebands distinguishable.
Hilbert transform: A signal-processing operation that shifts each frequency component by 90 degrees, with the sign determined by frequency. It creates the quadrature signal used to cancel one sideband.
High frequency: The radio-frequency band from 3 to 30 megahertz, used for communications including long-distance skywave links. Single-sideband transmissions commonly use this band for long-range voice.
Conventional amplitude modulation: Amplitude modulation that transmits a carrier and both sidebands. It simplifies reception by retaining the carrier, at the cost of greater power and bandwidth.
Beat frequency: A low-frequency variation produced when two oscillations of nearby frequencies combine. A small carrier-frequency error appears as an audible beat in received speech.
Phasing method: A single-sideband generation technique that combines phase-shifted message and carrier signals to cancel an unwanted sideband. This method generates single-sideband signals through precise phase cancellation.
Skywave propagation: Radio propagation in which signals refract in the ionosphere and return to Earth beyond the horizon. It enables high-frequency single-sideband signals to reach distant stations.

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