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In radio communications, a sideband is a band of frequencies higher than or lower than the carrier frequency, containing energy as a result of the modulation process. While all forms of modulation have sidebands by definition, it is most commonly discussed in amplitude modulation (AM). A band is a small section of the spectrum of radio communication frequencies, in which channels are usually used or set aside for the same purpose. ...
Sine waves of various frequencies; the lower waves have higher frequencies than those above. ...
Carrier frequency is the fundamental frequency used in both amplitude modulation and frequency modulation i. ...
Modulation is the process of varying a carrier signal, typically a sinusoidal signal, in order to use that signal to convey information. ...
Amplitude modulation (AM) is a form of modulation in which the amplitude of a carrier wave is varied in direct proportion to that of a modulating signal. ...
Amplitude modulation of a carrier wave normally results in two sidebands. The frequencies 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. A carrier wave is a waveform (usually sinusoidal) that is modulated (modified) to represent the information to be transmitted. ...
In communications, transmission is the act of transmitting electrical messages (and the associated phenonomena of radiant energy that pass through media). ...
If part of one sideband and all of the other remain, it is called vestigial sideband, used mostly with television broadcasting, which would otherwise take up an unacceptable amount of bandwidth. Transmission in which only one sideband is transmitted is called single-sideband transmission (SSB, particularly USB and sometimes LSB), used mainly in amateur radio. Broadcasting is the distribution of audio and video signals (programs) to a number of recipients (listeners or viewers) that belong to a large group. ...
// Analog For analog signals, bandwidth is the width, usually measured in hertz, of a frequency band f2 − f1. ...
Single-sideband transmission (SSB) is a method of transmitting audio based on amplitude modulation in which only one sideband is transmitted. ...
Amateur radio, commonly called ham radio, is a hobby enjoyed by many people throughout the world (as of 2004 about 3 million worldwide, 60,000 in UK, 70,000 in Germany, 11,000 in Sweden, 5,000 in Norway, 57,000 in Canada, 1400,000 each in South Korea and...
In many cases, particularly in amateur radio, a suppressed carrier is used, significantly reducing the amount of electrical power used (by up to 12 times), while still leaving the audio or other information present in the sideband. In this case, a beat frequency oscillator must be used at the receiver to reconstitute the signal. Reduced-carrier transmission is an amplitude modulation (AM) transmission in which the carrier wave level is reduced to reduce wasted electrical power. ...
Transmission lines in Lund, Sweden Electric power, often known as power or electricity, involves the production and delivery of electrical energy in sufficient quantities to operate domestic appliances, office equipment, industrial machinery and provide sufficient energy for both domestic and commercial lighting, heating, cooking and industrial processes. ...
Audio can mean: sound that can be heard electronics or other signals of frequencies audible to humans (about 20--20,000 Hz) broadcasting or reception of sound high-fidelity sound reproduction sound recording and reproduction in general means I hear in Latin Audible can also refer to Audible. ...
A beat frequency oscillator or BFO in radio telegraphy, is a dedicated oscillator used to create an audio frequency signal for carrier wave transmissions to make them audible, as they are not broadcast as such. ...
The word receiver has a number of different meanings: In communications and information processing, a receiver is the recipient (observer) of a message (information), which is sent from a source (object). ...
Signaling, or a signal, may mean: Look up signal in Wiktionary, the free dictionary Scientific concepts In information theory, a signal is a flow of information that can be represented as a mathematical function. ...
Sidebands are also what cause interference to adjacent channels, and therefore they must be suppressed by filters, either before or after modulation (or often both). In frequency modulation (FM), subcarriers above 75 kHz are suppressed to a small percentage of modulation, and are prohibited above 99 kHz altogether, in order to protect the ±75 kHz normal deviation and ±100 kHz channel boundaries. Interference of two circular waves - Wavelength (decreasing bottom to top) and Wave centers distance (increasing to the right). ...
In broadcasting an adjacent channel is an AM, FM, or TV channel that is next to another channel. ...
Electronic filters are electronic circuits which perform signal processing functions. ...
Frequency modulation (FM) is a form of modulation which represents information as variations in the instantaneous frequency of a carrier wave. ...
A subcarrier is separate analog or digital signal carried on a main radio transmission, which carries extra information such as voice or data. ...
A kilohertz (kHz) is a unit of frequency equal to 1,000 hertz (1,000 cycles per second). ...
A percentage is a way of expressing a proportion, a ratio or a fraction as a whole number, by using 100 as the denominator. ...
In radio, frequency deviation is the result of frequency modulation. ...
Look up Channel in Wiktionary, the free dictionary In general, channel refers to the path between two endpoints. ...
link titleBold text==See also==
Single-sideband modulation (SSB) is a refinement of the technique of amplitude modulation designed to be more efficient in its use of electrical power and bandwidth. ...
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