SMART ANTENNAS SMART ANTENNAS apoorva k. Shetti 2bu09ec006 PRESENTATION BY apoorva k. Shetti 2bu09ec006 UNDER THE GUIDANCE OF Lect. AMARJEETSINGH THAKUR PRESENTED BY Mr. apoorva k. Shetti

CONTENTS INTRODUCTION TYPES OF SMART ANTENNAS COMPARISION BETWEEN SWITCHED BEAM AND ADAPTIVE ARRAY SDMA(SPACE DIVISION MULTIPLE ACCESS) ADVANTAGES AND DISADVANTAGES APPLICATION CONCLUSION REFERENCES

INTRODUCTION Antenna is electrical device which converts electric power into electromagnetic waves or vice versa. Omni directional and directional antennas. Multipath and Co channel Interference. Figure A:Omni directional antenna B. Directional antenna coverage pattern coverage pattern

Figure : Smart antenna analogy with human What is SMART ANTENNA ? A smart antenna consists of an antenna array, that changes the array pattern in response to signal environment to improve the performance of a communication system. Figure : Smart antenna analogy with human

THE AIM OF SMART ANTENNA SYSTEM To maximize the antenna gain in the desired direction. To minimize the gain in directions of interferers.

TYPES OF SMART ANTENNA SWITCHED BEAM ANTENNA - a finite number of fixed ,predefined patterns. ADAPTIVE ARRAY ANTENNA - an infinite number of patterns (scenario based) that are adjusted in real time.

SWITCHED BEAM ANTENNAS This systems form multiple fixed beams with heightened sensitivity in particular directions. When incoming signal detected it determines the beam which is best aligned based on SOI and switches to that beam to communicate with user. As the mobile unit moves throughout the cell, the switched-beam system detects the signal strength and continually switches the beams as necessary.

Figure- Switched Beam System Coverage Patterns (Sectors) Contd… Figure- Switched Beam System Coverage Patterns (Sectors) It subdivides sector into many narrow beams, then each beam is considered as individual sector serving user or group of users.

Figure : Block diagram of Switched beam systems Contd... Figure : Block diagram of Switched beam systems PSN, which forms multiple beams looking in certain directions. RF Switch actuates the right beam in the desired direction.

Contd… The selection of right beam is made by control logic which is governed by an algorithm. The algorithm which scans all the beams and selects the one strongest receiving signal based on a measurement made by the detector. The overall goal of the switched-beam system is to increase the gain according to the location of the user.

ADAPTIVE ARRAY ANTENNAS Systems are really smart because they are able to dynamically react to the changing RF environment with its infinite scenario based patterns. They can direct the main beam toward the SOI(Signal Of Interest) while suppressing the antenna pattern in the direction of the interferers. It can customize an appropriate radiation pattern for each individual user. Dynamically adjust the antenna pattern to enhance reception while minimizing or fully rejecting interference .

Figure- Adaptive Array System Coverage Pattern Contd… Figure- Adaptive Array System Coverage Pattern This provides optimal gain while simultaneously identifying, tracking, and minimizing interfering signals.

Figure : Block diagram of Adaptive array systems Contd… Figure : Block diagram of Adaptive array systems D/C : Converts from RF to IF. ADC : Converts Analog to Digital for further processing. W’s : It contains amplification and phase information

SPACE DIVISION MULTIPLE ACCESS Among the most sophisticated utilization of smart antenna technology. It employs advanced technique to, in effect, locate and track fixed and mobile terminals, adaptively steering transmission signal toward user and interferers. Beams are sliced to keep different users in different beams at the same frequency which allows reuse of frequency. This technology achieves superior levels of interference suppression and reduces RF pollution.

Contd… Figure: SDMA technology(general and actual mechanism) This is the next step in an evolutionary path towards increasing the capacity of cellular systems

COMPARISION OF SWITCHED BEAM ANTENNA AND ADAPTIVE ARRAYS CRITERIA SWITCHED BEAM ADAPTIVE ARRAYS INTEGERATION Easy to implement Low cost Transceiver complexity High cost RANGE/COVERAGE More coverage compared to conventional systems Less coverage compared to adaptive array compared to switched beam system INTERFERENCE REJECTION Difficulty in distinguishing between desired signal and interferer Does not react to the movement of Interferers. Focusing is narrower Capable of nulling interfering signals

ADVANTAGES OF SMART ANTENNA Enhance coverage through Range extension. Fully controllable by software so less manual operations. Reduction in transmitted power. Reduce co-channel interference (CCI) and multipath interference. Provides high security. Improve system capacity. Compatibility, it can be applied to various multiple access techniques such as TDMA,FDMA ,and CDMA.

Smart Antenna’s Drawbacks Their transceivers are much more complex than traditional base station transceivers. Expensive.

APPLICATION Cellular and wireless networks Electronic warfare (EWF) as a countermeasure to electronic jamming Satellite systems

CONCLUSION Smart antennas are the intelligent antenna systems that vastly improve the efficiency of wireless transmission. SAS can achieve high transmission data rate and coverage area by effectively reducing multipath and co channel interference. Smart antenna systems are software-controllable, remotely configurable. Promising technology to resolve the traffic capacity .

References [1].R. H .Roy, “An overview of smart antenna technology and its application on wireless communication systems,” Proc .IEEE conf.personal wireless comm.,2007, pp. 234 – 238 [2].Chryssomallis, M., 2008. Smart antennas , IEEE Antennas and Propogation Magazine, 42(3): 129 -136 [3].S. F. Shaukat , Mukhtar ul Hassan, R. Farooq, H. U. Saeed and Z. Saleem, “Sequential studies of beam forming algorithms for smart antenna systems”, world applied sciences journal , vol .6, no. 6, pp 754-758,2009 [4].http://www.iec.org [5].http://www.smartantennas.googlepages.com