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smart antennas ppt

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smart antennas ppt

  2. 2. Agenda  History  Introduction  What is smart antenna?  Functioning of smart antenna.  Types of smart antenna.  Digital beam forming  DOA estimation  Advantages  Application and conclusion  References
  3. 3. History  The Smart Antenna was developed for “Military Communications” and “Intelligence gathering”.  New opportunities were created for smart antenna in the year 1990 by satellite broadcasting industries.
  4. 4. Introduction  Antenna is electrical device which converted electric power into electromagnetic waves.  A smart Antenna consist of an antenna array, that changes the array pattern in response to signal environment to improve the performance of a communication channel.  Smart antenna is not smart, it is the digital signal processing, along with the antennas, which makes the system smart.
  5. 5. What is Smart Antenna?  A Smart Antenna system combines an antenna array with a digital signal processing capability to transmit and receive in an adaptive manner.
  6. 6. Difference between regular antenna and smart antenna?  Regular antenna(omnidirectional): generates beams in all directions.  Having directional pattern in orthogonal plane and non-directional pattern in given plane.  Smart antenna: adaptive antenna utilizes adaptive DSP based techniques and digital technology.
  7. 7. Co-channel interference Co-channel interference:  Is a crosstalk from two different radio transmitter using same frequency.  CCI arises in the cellular mobile networks owing to this phenomenon of frequency reuse.
  8. 8. Functioning of Smart Antennas  The functioning of smart antennas is still far from being well defined, and many concepts are subject to thorough studies.  Technical aspects involve number of elements, fed with signals which are adaptively processed by space or space-time filtering.
  9. 9. Functioning of SA cont…….  Potential demands (generally hard to fulfil) are put on the functioning of smart antennas: 1. Increased number of subscribers(higher system capacity) 2. Higher data transmission rate. 3. Better spectral efficiency 4. Extended range 5. Processing of multipath propagated signals 6. Flexibility of channel transfer
  10. 10. Types of Smart antennas  There are three types of smart antennas are there: 1. Adaptive array antenna 2. Switched beam array antenna
  11. 11. Adaptive array antennas  Has become a core system component in future generation mobile networks.  Adaptive array allow the antenna to steer the beam to any direction of interest while simultaneously nulling interfering signals.  This antennas can track and locate signals.
  12. 12. Antenna architecture of AAS
  13. 13. Switched beam array antennas  They have several available fixed beam patterns.  Decision has to be made which beam has to be access at any given point of time.  Overall goal of the switched beam system is to increase gain according to the location of user. Antenna Array Active Beam
  14. 14. Block diagram of switched beam antenna
  15. 15. Comparison b/w switched and adaptive array antenna
  16. 16. Digital Beam Forming  The digital beam forming segment of the smart antenna comprises two modules: 1. communication and calibration signal processing. 2. Beam forming processors.
  17. 17. DBF cont…..  In communication and calibration signal processing needs a very high data rate and calls for a large computational power.  In the beam forming processor needs a lower rate of weight update which usually ranges up to a few kHz.
  18. 18. DOA(Direction Of Arrival) estimation  It is direction of arrival  The smart antenna estimates the direction of arrival of the signal, using technique such as MUSIC(Multiple Signal Classification) estimation of signal parameters via Matrix pencil method or one of their derivatives.  They involve finding a spatial spectrum of the antenna and calculating the DOA from the peaks of this spectrum.
  19. 19. Advantages of smart antennas  Reduction in co-channel interference.  Range improvement  Increase in capacity  Reduction in transmitted power.  Reduction in handoff.
  20. 20. Applications  Mobile communications  Cellular and wireless network.  Satellite communication.  Wireless sensor network.  Military.  Electronic warfare
  21. 21. Future scope  In mobile handsets to achieve much better performance.  4G system with 1 Gbit/s data rate and frequency 20-100Mhz.  Detect malignant tumours
  22. 22. conclusion  Smart antenna are the intelligent antenna systems that improve the efficiency of wireless transmission.  Promising technology to resolve the traffic capacity.  Efficient utilization of the scarcest resource of todays wireless communication.
  23. 23. References [1] Dau-Chyrh Chang and Cheng-Nan Hu, “Smart Antennas for Advanced Communication Systems”-vol.100,no.7, July 2012. [2] Daniel J Bern, Pawel Kabacik,-”Smart Antennas for Mobile Communication Systems”. [3]Nihad A. A. Elhag, Islam M Osman, Alaa A Yassin, Tsneem B Ahmed,”Angle of Arrival Estimation in Smart Antenna Using MUSIC method for Wideband Wireless Communication” IEEE 2013. [4]T. Nageswara Rao, V. Srinivasa Rao, “Evaluation of MUSIC algorithm for a Smart Antenna system for Mobile Communications”.
  24. 24. Thank you