Smart antenna

China Product


Direction of arrival (DOA) estimation

The smart antenna system estimates the direction of arrival of the signal, using techniques such as MUSIC (Multiple Signal Classification), estimation of signal parameters via rotational invariance techniques (ESPRIT) algorithms, Matrix Pencil method or one of their derivatives. They involve finding a spatial spectrum of 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. garmin gps 72 handheld gps

Beamforming cherished numbers

Beamforming is the method used to create the radiation pattern of 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 . gps receiver modules

Types of smart antennas

Two of the main types of smart antennas include switched beam smart antennas and adaptive array smart 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 . Beamdirection can be estimated using the so-called direction-of-arrival (DOA) estimation methods .

In 2008, the United States NTIA began a major effort to assist consumers in the purchase of digital television converter boxes. 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-909 Standard Interface.

Extension of smart antennas

Smart antenna systems are also a defining characteristic of MIMO systems, such as the IEEE 802.11n standard. 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.

References

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

http://broadcastengineering.com/hdtv/smart_antennas/

Handbook on Advancements in Smart Antenna Technologies for Wireless Networks, IGI 2008

http://users.ece.utexas.edu/~bevans/courses/ee381k/lectures/13_Array_Processing/lecture13/lecture13.pdf : Array Processing Tutorial

See also

Antenna (radio)

Array processing

Phased array

CEA-909

Mimax

diversity combining

v  d  e

Digital television in North America

Digital television

Terrestrial

Digital broadcasting

ATSC tuners  Digital subchannels  Virtual channels  Distributed transmission system  Datacasting (Guide Plus  National Datacast  UpdateLogic)  Metropolitan Television Alliance  Grand Alliance

Digital switchover

All-Channel Receiver Act  SAFER Act  Digital channel election  Set-top boxes  Digital television adapter  U.S. Converter Box Coupon Program (boxes, legislation)  Analog passthrough  DVD recorders  Digital video recorders

Digital standards

ATSC Standards (ATSC  ATSC-M/H  8VSB  A-VSB  E-VSB  PSIP  PMCP  full list)  Standard-definition TV (480i  576i)  Enhanced-definition TV (480p  576p)  High-definition TV (720p  1080i  1080p)  Serial digital interface  Smart antennas (CEA-909)

Digital networks

see Template:American broadcast television

National deployment

List by country  Canada   Mexico   United Kingdom   United States (HDTV  transition  wireless spectrum auction)

Cable

Digital cable

Digital-cable-ready TV (QAM tuners)  Interactive-digital-cable-ready TV (OpenCable Application Platform  Advanced Common Application Platform)  Must-carry  Tru2way

Subscription TV

Encryption  CableCARD  Downloadable Conditional Access System

Satellite TV

DVB-S (Dish Network  GlobeCast World TV  Free-to-air receiver  Bell TV)  DigiCipher 2 (4DTV  Shaw Direct)  Digital Satellite Service/DVB-S2 (DirecTV)

Technical issues

14:9  Active Format Description  Broadcast flag  Channel protection ratios  HDTV blur  Hierarchical modulation  Pirate decryption  Standards conversion  Video on demand

Categories: Radio frequency antenna types