SMART ANTENNAS AND SMART ANTENNAS AND MIMO SYSTEMSMIMO SYSTEMS

Guide: By:Guide: By:

Mrs. Bindu E. Raja Rajput Mrs. Bindu E. Raja Rajput

ECE(4ECE(4thth year) year)

Group No. 11 Group No. 11

OVERVIEWOVERVIEW• Introduction• What makes SA smart?• Antenna Arrays• Working of smart antennas• Benefits and drawbacks• Applications• SA classification and comparison• MIMO: Extension of smart antennas• Diversity techniques• Conclusion• References

INTRODUCTIONINTRODUCTIONSMART ANTENNAS:• A smart antenna is an array of antenna

elements connected to a digital signal processor.

MIMO: SMART ANTENNAS EXTENSION• A smart antenna performs spatial signal

processing with multiple antennas which can be used at either the transmitter or receiver, called as MIMO systems.

WHAT MAKES SMART WHAT MAKES SMART ANTENNA SMART?ANTENNA SMART?

• SA smartness reside in their digital signal-processing facilities.

DOA calculation & beamforming

ANTENNA ARRAYSANTENNA ARRAYS• Assembly of radiating elements in a special

geometrical configuration without increasing the size of the individual elements.

1-D 2-D

2-D 3-D

WORKING OF SMART ANTENNAWORKING OF SMART ANTENNA• Smart antenna as Transmitter:

• Beamformer weights multiplication Beamformer weights multiplication on the basis of DOA.on the basis of DOA.

• Smart antenna as Receiver:

BENEFITSBENEFITS• Reduced Interference : Radiates in DOA of

the signals only.

• Increased Capacity : Better frequency reuse due to reduced interference. Larger no. of users.

• Increased Range : DSP decides the range.

• Low Power Consumption : Due to limited radiation pattern unlike omnidirectional antennas

• Security : Radiation pattern.• Easily Integrated

DRAWBACKSDRAWBACKS• Complexity : DSP and Antenna Array.• Expensive : Multi-radiating elements

used. • Larger Size : Due to Antenna Array.• Difficult to use in Mobile Sets due to

larger size.

APPLICATIONSAPPLICATIONS• MIMO systems• Cellular systems• Positioning and Tracking systems• Satellite systems• RADAR

SMART ANTENNA SMART ANTENNA CLASSIFICATIONCLASSIFICATION

• Switched Beam antenna: Finite number of fixed predefined patterns or combining strategies by antenna arrays.

• Butler matrix is commonly used for multiple beamforming.

Butler MatrixOutput

• Adaptive antenna arrays: it locates the SOI using the direction-of-arrival (DOA) algorithm for example MUSIC.

• Enhancing SOI and suppress SNOI by creating nulls.

Coverage patterns for switched Coverage patterns for switched beam and adaptive array beam and adaptive array antennas:antennas:

Comparing coverage patterns in presence and in absence of interference.

MIMO: SMART ANTENNA MIMO: SMART ANTENNA EXTENSIONEXTENSION

Devices with SA acting as transmitter as well as receiver with multi-path signals.

SA MIMO improves the wireless SA MIMO improves the wireless communication by Diversity:communication by Diversity:

Diversity: To improve the performance of communication it is important to ensure that the information symbols pass through multiple signal paths, each of which fades independently, making sure that reliable communication is possible as long as one of the paths is strong. This technique is called diversity.

Diversity TechniquesDiversity Techniques• Time diversity: Diversity over time can be

obtained via coding and interleaving which finally effects fading.

• Frequency diversity: Signal is transmitted simultaneously using several frequency channels in which signals suffer from different fading values.

• Antenna diversity (or spatial diversity): By placing multiple antennas at the transmitter and/or the receiver. If the antennas are placed sufficiently far apart, different antenna pairs fade more or less independently.

• Polarization diversity: Vertically and horizontally polarized waves will encounter different fading.

CONCLUSIONCONCLUSION• “Smart Antenna” systems are the antennas arrays with

intelligence and the radiation pattern can be varied without being mechanically changed.

• With appropriate adaptive algorithms the beam forming can be obtained.

• As the system uses a DSP processor the signals can be processed digitally and the performance is with a high data rate transmission and good reduction of mutual signal interference.

• Further, smart antennas reduces fading. This in turn allows the increase in capacity of existing or future mobile communications networks.

• Geometry of the antenna array was discussed. Finally, future developments which include MIMO systems were explained which promise huge transmission capacities.

REFERENCESREFERENCES• Constantine A. Balanis, Panayiotis I.

Ioannides, “Introduction to Smart Antennas” (1st Edition), Morgan & Claypool Publication.

• David Tse, Pramod Vishwanath, “Fundamentals of Wireless Communication”(1st edition)”, Cambridge University Press Publication.