Technical Paper Presentation on

Presented by:Shreedhar Subhas Electronics and Communication EngineeringDate:12-09-2015

Reconfigurable Filtennas and MIMO in Cognitive Radio Applications

What is cognitive Radio?

Cognitive Radios(CRs) intelligent System which Allows the unlicensed users to access the unutilized part of licensed bands with a specific time and locations.

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The main purpose of adopting cognitive radio technology is to improve the spectrum usage efficiency.

Cognitive Radio(CR) System Allows the unlicensed users to dynamically access the “under-utilized" licensed bands.

The huge development of personal wireless technologies like - Wi-Fi, Bluetooth, digital phones, and so on which operate on unlicensed band.

Why cognitive Radio..??

What is Reconfigurable Filtennas?

Filtennas = Filter + Antennas

Reconfigurable : reconfigurable antennas is used to maximize the antenna performance in a changing scenario or to satisfy changing operating requirements.

Working:

A cognitive radio system learns from previous experiences and channel activity and adapts itself based on this information.

Principle :

MIMO (Multiple Input Multiple Output)

Provide increased link capacity and spectral efficiency combined with improved links.

Underlay cognitive Radio System

(a)Top layer (b)Bottom layer[all dimensions in mm ]

(a) the top layer (b) the bottom layer with the integrated switches.

Fabricated underlay cognitive radio antenna

(a) (b)

f [G Hz] Total Efficiency

S1/s2 OFF 3.93 65%

S1/s2 ON 4.35 74%

S1 ON 4.08 63%

VALUES FOR THE RECONFIGURABLE FILTENNA

f [Ghz] Total Efficiency

S1/s2 OFF 3.93 65%

S1/s2 ON 4.35 74%S1 ON 4.08 63%

VALUES FOR THE RECONFIGURABLE FILTENNA

Typical Cognitive Radio Applications

Implemntation Issues:Complexity in Sensing

algorithms designSecurityShort range communication

with power level restriction

CONCLUSION

REFERENCES[1] S. K. Jayaweera and C. G. Christodoulou, “Radiobots: Architecture,Algorithms and Real-Time Reconfigurable Antenna Designsfor Autonomous, Self-Learning Future Cognitive Radios,”Univ. New Mexico, Tech. Re. [Online]. Available: http://repository.unm.edu/handle/1928/12306

[2] S. Haykin, “Cognitive radio: Brain-empowered wireless communications,”IEEE J. Sel. Areas Commun., vol. 23, pp. 201–220, 2005.

[3] Y. Tawk and C. G. Christodoulou, “A new reconfigurable antenna designfor cognitive radio,” IEEE Antennas Wireless Propag. Lett., vol.8, pp. 1378–1381, 2009.

[4] Y. Tawk, M. Bkassiny, G. El-Howayek, S. K. Jayaweera,K.Avery, andC. G. Christodoulou, “Reconfigurable front-end antennas for cognitiveradio applications,” IET, Microwaves, Antennas Propag., vol. 5, no. 8,pp. 985–992, Jun. 2011.

[5] A. Grau, J. Romeu, M. Lee, S. Blanch, L. Jofre, and F. De Flaviis, “Adual linearly polarized MEMS-reconfigurable antenna for narrowbandMIMO communication systems,” IEEE Trans.

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