In
telecommunication
Telecommunication, often used in its plural form or abbreviated as telecom, is the transmission of information over a distance using electronic means, typically through cables, radio waves, or other communication technologies. These means of ...
s, an interference is that which modifies a
signal
A signal is both the process and the result of transmission of data over some media accomplished by embedding some variation. Signals are important in multiple subject fields including signal processing, information theory and biology.
In ...
in a disruptive manner, as it travels along a
communication channel
A communication channel refers either to a physical transmission medium such as a wire, or to a logical connection over a multiplexed medium such as a radio channel in telecommunications and computer networking. A channel is used for infor ...
between its
source and receiver. The term is often used to refer to the addition of unwanted signals to a useful signal. Common examples include:
*
Electromagnetic interference (EMI)
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Co-channel interference (CCI), also known as
crosstalk
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Adjacent-channel interference
Adjacent-channel interference (ACI) is interference caused by extraneous power from a signal in an adjacent channel. ACI may be caused by inadequate filtering (such as incomplete filtering of unwanted modulation products in FM systems), improp ...
(ACI)
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Intersymbol interference (ISI)
* Inter-carrier interference (ICI), caused by doppler shift in
OFDM modulation (multitone modulation).
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Common-mode interference (CMI)
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Conducted interference
Noise
Noise is sound, chiefly unwanted, unintentional, or harmful sound considered unpleasant, loud, or disruptive to mental or hearing faculties. From a physics standpoint, there is no distinction between noise and desired sound, as both are vibrat ...
is a form of interference but not all interference is noise.
Radio resource management aims at reducing and controlling the
co-channel and
adjacent-channel interference
Adjacent-channel interference (ACI) is interference caused by extraneous power from a signal in an adjacent channel. ACI may be caused by inadequate filtering (such as incomplete filtering of unwanted modulation products in FM systems), improp ...
.
Interference alignment
A solution to interference problems in
wireless
Wireless communication (or just wireless, when the context allows) is the transfer of information (''telecommunication'') between two or more points without the use of an electrical conductor, optical fiber or other continuous guided transm ...
communication networks is interference alignment, which was crystallized by
Syed Ali Jafar at the
University of California, Irvine
The University of California, Irvine (UCI or UC Irvine) is a Public university, public Land-grant university, land-grant research university in Irvine, California, United States. One of the ten campuses of the University of California system, U ...
.
A specialized application was previously studied by Yitzhak Birk and Tomer Kol for an index coding problem in 1998. For interference management in wireless communication, interference alignment was originally introduced by Mohammad Ali Maddah-Ali, Abolfazl S. Motahari, and Amir Keyvan Khandani, at the University of Waterloo, for communication over wireless X channels. Interference alignment was eventually established as a general principle by Jafar and Viveck R. Cadambe in 2008, when they introduced "a mechanism to align an arbitrarily large number of interferers, leading to the surprising conclusion that
wireless networks are not essentially interference limited." This led to the adoption of interference alignment in the design of wireless networks.
Jafar explained:
According to
New York University
New York University (NYU) is a private university, private research university in New York City, New York, United States. Chartered in 1831 by the New York State Legislature, NYU was founded in 1832 by Albert Gallatin as a Nondenominational ...
senior researcher
Paul Horn:
See also
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Distortion
In signal processing, distortion is the alteration of the original shape (or other characteristic) of a signal. In communications and electronics it means the alteration of the waveform of an information-bearing signal, such as an audio signal ...
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Inter-flow interference
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Intra-flow interference
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Meaconing
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Signal-to-interference ratio (SIR)
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Signal-to-noise plus interference (SNIR)
References
External links
Overview of interference mitigation techniques in mobile networks
{{DEFAULTSORT:Interference (communication)
Noise (electronics)
Interference
Telecommunications
fr:Interférence