Independent sideband (ISB) is an AM

single sideband In radio communications, single-sideband modulation (SSB) or single-sideband suppressed-carrier modulation (SSB-SC) is a type of modulation used to transmit information, such as an audio signal, by radio waves. A refinement of amplitude m ...

mode Mode ( la, modus meaning "manner, tune, measure, due measure, rhythm, melody") may refer to: Arts and entertainment * '' MO''D''E (magazine)'', a defunct U.S. women's fashion magazine * ''Mode'' magazine, a fictional fashion magazine which is ...

which is used with some

AM radio AM broadcasting is radio broadcasting using amplitude modulation (AM) transmissions. It was the first method developed for making audio radio transmissions, and is still used worldwide, primarily for medium wave (also known as "AM band") transmis ...

transmissions. Normally each

sideband In radio communications, a sideband is a band of frequencies higher than or lower than the carrier frequency, that are the result of the modulation process. The sidebands carry the information transmitted by the radio signal. The sidebands c ...

carries identical information, but ISB modulates two different input signals — one on the

upper sideband In radio communications, a sideband is a band of frequencies higher than or lower than the carrier frequency, that are the result of the modulation process. The sidebands carry the information transmitted by the radio signal. The sidebands com ...

, the other on the

lower sideband In radio communications, a sideband is a band of frequencies higher than or lower than the carrier frequency, that are the result of the modulation process. The sidebands carry the information transmitted by the radio signal. The sidebands com ...

. This is used in some kinds of AM stereo (sometimes known as the

Kahn Kahn is a surname of German origin. ''Kahn'' means "small boat", in German. It is also a Germanized form of the Jewish surname Cohen, another variant of which is '' Cahn''.

system). ISB is a compromise between

double sideband In radio communications, a sideband is a band of frequencies higher than or lower than the carrier frequency, that are the result of the modulation process. The sidebands carry the information transmitted by the radio signal. The sidebands com ...

(DSB) and

(SSB) — the other is

vestigial sideband In radio communications, single-sideband modulation (SSB) or single-sideband suppressed-carrier modulation (SSB-SC) is a type of modulation used to transmit information, such as an audio signal, by radio waves. A refinement of amplitude m ...

(VSB). If the sidebands are

out of phase In physics and mathematics, the phase of a periodic function F of some real variable t (such as time) is an angle-like quantity representing the fraction of the cycle covered up to t. It is denoted \phi(t) and expressed in such a scale that it ...

with each other, then

phase modulation Phase modulation (PM) is a modulation pattern for conditioning communication signals for transmission. It encodes a message signal as variations in the instantaneous phase of a carrier wave. Phase modulation is one of the two principal forms of ...

(PM) of the carrier occurs. AM and PM together then create

quadrature amplitude modulation Quadrature amplitude modulation (QAM) is the name of a family of digital modulation methods and a related family of analog modulation methods widely used in modern telecommunications to transmit information. It conveys two analog message signa ...

(QAM). ISB may or may not have the carrier suppressed. Suppressed-carrier ISB was employed in point-to-point (usually overseas)

radiotelephony A radiotelephone (or radiophone), abbreviated RT, is a radio communication system for conducting a conversation; radiotelephony means telephony by radio. It is in contrast to ''radiotelegraphy'', which is radio transmission of telegrams (messag ...

and

radioteletype Radioteletype (RTTY) is a telecommunications system consisting originally of two or more electromechanical teleprinters in different locations connected by radio rather than a wired link. Radioteletype evolved from earlier landline teleprinter ...

by shortwave ( HF). In military use, ISB usually referred to a close pair of FSK radioteletype channels which could be demodulated by a single receiver, and employed in fleet broadcast, point-to-point, and between larger vessels and shore stations on HF and UHF.

References

{{DEFAULTSORT:Independent Sideband Radio modulation modes