- Smart antenna
Smart antennas (also known as adaptive array antennas, multiple antennas and recently MIMO) are
antenna arrays with smart signal processing algorithms used to identify spatial signal signature such as the direction of arrival(DOA) of the signal, and use it to calculate beamformingvectors, to track and locate the antenna beam on the mobile/target. The antenna could optionally be any sensor.
Smart antenna techniques are used notably in acoustic signal processing, track and scan
RADAR, radio astronomyand radio telescopes, and mostly in cellular systems like W-CDMAand UMTS.
Smart antennas have two main functions:
# DOA estimation
The smart antenna system estimates the direction of arrival of the signal, using techniques such as MUSIC (Multiple Signal Classification), ESPRIT (Estimation of Signal Parameters via Rotational Invariant Techniques) algorithms, Matrix Pencil method or one of their derivatives. They involve finding a
spatial spectrumof the antenna/sensor array, and calculating the DOA from the peaks of this spectrum. These calculations are computationally intensive.
Matrix Pencil is very efficient in case of real time systems, and under the correlated sources.
Beamformingis the method used to create the radiation patternof the antenna array by adding constructively the phases of the signals in the direction of the targets/mobiles desired, and nulling the pattern of the targets/mobiles that are undesired/interfering targets.This can be done with a simple FIR tapped delay line filter. The weights of the FIR filter may also be changed adaptively, and used to provide optimal beamforming, in the sense that it reduces the MMSE between the desired and actual beampattern formed. Typical algorithms are the steepest descent, and LMS algorithms  .
Types of smart antennas
Two of the main types of smart antennas include
switched beamsmart antennas and adaptive arraysmart antennas. Switched beam systems have several available fixed beam patterns. A decision is made as to which beam to access, at any given point in time, based upon the requirements of the system. Adaptive arrays allow the antenna to steer the beam to any direction of interest while simultaneously nulling interfering signals  .
In 2008, the United States NTIA began a major effort to assist consumers in the purchase of digital television converter boxes. [http://www.dtv2009.gov/] Through this effort, many people have been exposed to the concept of smart antennas for the first time. In the context of consumer electronics, a "smart antenna" is one that conforms to the EIA/
CEA-909Standard Interface, such as the DX DTA-5000. [http://www.solidsignal.com/prod_display.asp?PROD=DTA5000] [http://www.summitsource.com/dx-antenna-dta5000-tv-smart-antenna-multidirectional-hdtv-digital-uhf-vhf-outdoor-offair-high-definition-local-hd-sylvania-television-reception-aerial-green-zone-part-dta5000-p-6320.html]
Extension of smart antennas
Smart antenna systems are also a defining characteristic of MIMO systems, such as the proposed
IEEE 802.11nstandard. Conventionally, a smart antenna is a unit of a wireless communication system and performs spatial signal processing with multiple antennas. Multiple antennas can be used at either the transmitter or receiver. Recently, the technology has been extended to use the multiple antennas at both the transmitter and receiver; such a system is called a multiple-input multiple-output (MIMO) system. As extended Smart Antenna technology, MIMO supports spatial information processing, in the sense that conventional research on Smart Antennas has focused on how to provide a beamforming advantage by the use of spatial signal processing in wireless channels. Spatial information processing includes spatial information coding such as Spatial multiplexing and Diversity Coding, as well as beamforming.
# http://www.stanford.edu/group/sarg/ : Smart Antenna Research Group.
# http://www.mprg.org : Virginia Tech, Mobile and Portable & Radio research group
# Frank B. Gross, "Smart Antennas for Wireless Communications with Matlab", McGraw-Hill, 2005
Wikimedia Foundation. 2010.
Look at other dictionaries:
Antenna array — may refer to: *an interferometric array of Radio telescopes used in radio astronomy. *a Phased array, also known as a smart antenna, an electronically steerable directional antenna typically used in RADAR and in wireless communication systems, in … Wikipedia
Antenna (radio) — Whip antenna on car … Wikipedia
SMART-L — (Signaal Multibeam Acquisition Radar for Tracking, L band) is a long range search radar for naval ships developed by former Hollandse Signaalapparaten (Signaal), now Thales Naval Nederland. The Thales/BAE Systems Insyte S1850M radar is a… … Wikipedia
SMART 1 — (Small Missions for Advanced Research in Technology, – deutsch: Kleine Missionen für fortgeschrittene Technologiestudien) war die erste Raumsonde der ESA, die den Erdmond erforscht hat. Inhaltsverzeichnis 1 Missionsziele 2 Flugverlauf 2.1 Start 2 … Deutsch Wikipedia
Smart-1 — (Small Missions for Advanced Research in Technology, – deutsch: Kleine Missionen für fortgeschrittene Technologiestudien) war die erste Raumsonde der ESA, die den Erdmond erforscht hat. Inhaltsverzeichnis 1 Missionsziele 2 Flugverlauf 2.1 Start 2 … Deutsch Wikipedia
Smart label — Smart Label, also called Smart Tag, is an extremely flat configurated Transponder under a conventional print coded label, which includes chip, antenna and bonding wires as a so called inlay . The labels made of paper, fabric or plastics are… … Wikipedia
Smart card — This article is regarding smart cards that use electrical connectors to transmit data. For smart cards that use radio see contactless smart card Contact type smart cards may have many different contact pad layouts, such as these SIMs A smart card … Wikipedia
Antenna-Diversity — Der englische Begriff Antenna Diversity (deutsch Antennendiversität) bezeichnet ein Verfahren, bei dem mehrere Antennen pro Sender oder Empfänger verwendet werden, um Interferenz Effekte bei der Funkübertragung zu reduzieren. Dies ist besonders… … Deutsch Wikipedia
Antenna Diversity — Der englische Begriff Antenna Diversity (deutsch Antennendiversität) bezeichnet ein Verfahren, bei dem mehrere Antennen pro Sender oder Empfänger verwendet werden, um Interferenz Effekte bei der Funkübertragung zu reduzieren. Dies ist besonders… … Deutsch Wikipedia
Many Antenna — Many Antennas is a smart antenna technique, which overcomes the performance limitation of single user MIMO techniques. In cellular communications, the number of the maximum considered antennas for downlink is 2 and 4 to support LTE and IMT A… … Wikipedia