Interference (communication)

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In telecommunications, an interference is that which modifies a signal in a disruptive manner, as it travels along a communication channel 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:


Noise 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.

Interference alignment

A solution to interference problems in wireless communication networks is interference alignment, which was crystallized by Syed Ali Jafar at the University of California, Irvine. [1] 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. [2] 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. [3]

Jafar explained:

My research group crystallized the concept of interference alignment and showed that through interference alignment, it is possible for everyone to access half of the total bandwidth free from interference. Initially this result was shown under a number of idealized assumptions that are typical in theoretical studies. We have since continued to work on peeling off these idealizations one at a time, to bring the theory closer to practice. Along the way we have made numerous discoveries through the lens of interference alignment, which reveal new and powerful signaling schemes. [4]

According to New York University senior researcher Paul Horn:

Syed Jafar revolutionized our understanding of the capacity limits of wireless networks. He demonstrated the astounding result that each user in a wireless network can access half of the spectrum without interference from other users, regardless of how many users are sharing the spectrum. This is a truly remarkable result that has a tremendous impact on both information theory and the design of wireless networks. [1]

See also

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Syed Ali Jafar is an Indian-American electrical engineer and computer scientist. He works at the University of California, Irvine, and has previously worked at Lucent Bell Labs, Qualcomm and Hughes Software Systems. His research interests include multi-user information theory, wireless communications and network coding. He was named Fellow of the Institute of Electrical and Electronics Engineers (IEEE) in 2014 "for contributions to analyzing the capacity of wireless communication networks" and won the Blavatnik Award for Young Scientists in 2015 "for his discoveries in interference alignment in wireless networks, changing the field’s thinking about how these networks should be designed."

Salman A. Avestimehr

Salman A. Avestimehr is a Dean's professor at the Electrical and Computer Engineering Department of University of Southern California, where he is the inaugural Director of the USC-Amazon Center for Secure and Trusted Machine Learning and the director of the Information Theory and Machine Learning (vITAL) research lab. Avestimehr's contributions in research and publications are in the areas of information theory, machine learning, large-scale distributed computing, and secure/private computing and learning. In particular, he is best known for deterministic approximation approaches to network information theory and coded computing. He was a general co-chair of the 2020 International Symposium on Information Theory (ISIT), and is a Fellow of IEEE. He is also co-authors of four books titled “An Approximation Approach to Network Information Theory”, “Multihop Wireless Networks: A Unified Approach to Relaying and Interference Management”, “Coded Computing”, and “Problem Solving Strategies for Elementary-School Math.”


  1. 1 2 "2015 National Laureates". Blavatnik Awards for Young Scientists . June 30, 2015. Retrieved 22 September 2019.
  2. Maddah-Ali, Mohammad Ali; Motahari, S. Abolfazl; Khandani, Amir Keyvan (July 2008). "Communication over MIMO X channels: Interference alignment, decomposition, and performance analysis". IEEE Transactions on Information Theory. 54 (8): 3457–3470.
  3. Jafar, Syed A. (2010). "Interference Alignment — A New Look at Signal Dimensions in a Communication Network". Foundations and Trends in Communications and Information Theory. 7 (1): 1–134. CiteSeerX . doi:10.1561/0100000047.
  4. "Meet the Scientists: Syed A. Jafar". Armed With Science. United States Department of Defense. August 24, 2015. Retrieved 23 September 2019.