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Cognitive Radio Communications and Networks: Principles and Practice By A. M. Wyglinski, M. Nekovee, Y. T. Hou (Elsevier, December 2009) 1 Chapter 1 When.

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Presentation on theme: "Cognitive Radio Communications and Networks: Principles and Practice By A. M. Wyglinski, M. Nekovee, Y. T. Hou (Elsevier, December 2009) 1 Chapter 1 When."— Presentation transcript:

1 Cognitive Radio Communications and Networks: Principles and Practice By A. M. Wyglinski, M. Nekovee, Y. T. Hou (Elsevier, December 2009) 1 Chapter 1 When Radio Meets Software

2 Cognitive Radio Communications and Networks: Principles and Practice By A. M. Wyglinski, M. Nekovee, Y. T. Hou (Elsevier, December 2009) 2 Outline Motivation Software-Defined Radio Cognitive Radio Key Applications Chapter 1 Summary

3 Cognitive Radio Communications and Networks: Principles and Practice By A. M. Wyglinski, M. Nekovee, Y. T. Hou (Elsevier, December 2009) 3 Outline Motivation Software-Defined Radio Cognitive Radio Key Applications Chapter 1 Summary

4 Cognitive Radio Communications and Networks: Principles and Practice By A. M. Wyglinski, M. Nekovee, Y. T. Hou (Elsevier, December 2009) 4 The Information Age Data communications an integral part of modern society Financial transactions Social interactions Education National security Commerce

5 Cognitive Radio Communications and Networks: Principles and Practice By A. M. Wyglinski, M. Nekovee, Y. T. Hou (Elsevier, December 2009) Recent Growth Growing number of data applications and users Diverse services Voice telephony Web browsing Text messages Different performance requirements Bandwidth/data rate Latency Power consumption 5

6 Cognitive Radio Communications and Networks: Principles and Practice By A. M. Wyglinski, M. Nekovee, Y. T. Hou (Elsevier, December 2009) Increasing Demand Rapid growth in the wireless communications sector, requiring more spectral bandwidth Increasing number of users Increasing number of new wireless services being offered Some applications are bandwidth-intensive

7 Cognitive Radio Communications and Networks: Principles and Practice By A. M. Wyglinski, M. Nekovee, Y. T. Hou (Elsevier, December 2009) Maybe Too Much Growth? Spectrum scarcity due to command- and-control structure of frequency allocation Fixed amount of spectrum versus growing number of wireless applications/users License holders maintain exclusive rights to their allocated spectrum Purchased during a spectrum auction, e.g., 3G auctions Allocated via government decree, e.g., military, television

8 Cognitive Radio Communications and Networks: Principles and Practice By A. M. Wyglinski, M. Nekovee, Y. T. Hou (Elsevier, December 2009) Spectrum Scarcity Unlicensed devices not permitted to transmit in licensed bands Allocated unlicensed bands (with transmit constraints) Industrial, Scientific, Medical (ISM) bands 900 MHz, 1.8 GHz, 2.4 GHz, 5.8 GHz Unlicensed National Information Infrastructure (UNII) band 5.15 GHz – 5.825 GHz

9 Cognitive Radio Communications and Networks: Principles and Practice By A. M. Wyglinski, M. Nekovee, Y. T. Hou (Elsevier, December 2009) Conventional Wireless Devices Todays wireless devices are constrained in operation Fixed applications (e.g., cellular, WLAN) Fixed frequency bands of operation Fixed modes of operation (e.g., data rates, power levels)

10 Cognitive Radio Communications and Networks: Principles and Practice By A. M. Wyglinski, M. Nekovee, Y. T. Hou (Elsevier, December 2009) Interoperability Plethora of different wireless standards for a wide range of applications Tower of Babel syndrome Interoperability issues Public safety sector especially affected by these issues Need for reliable communications across platforms employing different communication standards

11 Cognitive Radio Communications and Networks: Principles and Practice By A. M. Wyglinski, M. Nekovee, Y. T. Hou (Elsevier, December 2009) Moores Law to the Rescue! Microelectronics evolution leading to increasingly sophisticated wireless system designs Versatility Computationally powerful Portability Over the past decade wireless devices have been employing programmable attributes 11

12 Cognitive Radio Communications and Networks: Principles and Practice By A. M. Wyglinski, M. Nekovee, Y. T. Hou (Elsevier, December 2009) 12 Outline Motivation Software-Defined Radio Cognitive Radio Key Applications Chapter 1 Summary

13 Cognitive Radio Communications and Networks: Principles and Practice By A. M. Wyglinski, M. Nekovee, Y. T. Hou (Elsevier, December 2009) 13 SDR: An Enabling Technology Rapidly programmable radio functions Device can assume any configuration available in memory Capable of performing on-the-fly transceiver optimization to enhance performance

14 Cognitive Radio Communications and Networks: Principles and Practice By A. M. Wyglinski, M. Nekovee, Y. T. Hou (Elsevier, December 2009) Motherboard FPGA DAC / ADC Daughterboards RF front-end Interchangeable Affordable = Accessible Universal Software Radio Peripheral 2 (USRP2) Unit Underneath the Hood

15 Cognitive Radio Communications and Networks: Principles and Practice By A. M. Wyglinski, M. Nekovee, Y. T. Hou (Elsevier, December 2009) Software Defined Radio Software or Programmable Logic

16 Cognitive Radio Communications and Networks: Principles and Practice By A. M. Wyglinski, M. Nekovee, Y. T. Hou (Elsevier, December 2009) Software Defined Radio RF Hardware

17 Cognitive Radio Communications and Networks: Principles and Practice By A. M. Wyglinski, M. Nekovee, Y. T. Hou (Elsevier, December 2009) 17 Outline Motivation Software-Defined Radio Cognitive Radio Key Applications Chapter 1 Summary

18 Cognitive Radio Communications and Networks: Principles and Practice By A. M. Wyglinski, M. Nekovee, Y. T. Hou (Elsevier, December 2009) What is a Cognitive Radio? An intelligent wireless communications system Based on SDR technology Reconfigurable Agile Functionality Aware of its environment RF spectrum occupancy Network traffic Transmission quality Learns from its environment and adapts to new scenarios based on previous experiences

19 Cognitive Radio Communications and Networks: Principles and Practice By A. M. Wyglinski, M. Nekovee, Y. T. Hou (Elsevier, December 2009) Cognitive Radio: Definition Cognitive radio is an intelligent wireless communication system that is aware of its surrounding environment (i.e., outside world), and uses the methodology of understanding-by-building to learn from the environment and adapt its internal states to statistical variations in the incoming RF stimuli by making corresponding changes in certain operating parameters (e.g., transmit-power, carrier-frequency, and modulation strategy) in real-time, with two primary objectives in mind: highly reliable communications whenever and wherever needed; efficient utilization of the radio spectrum. S. Haykin, Cognitive Radio: Brain-Empowered Wireless Communications, IEEE J-SAC, Feb. 2005.

20 Cognitive Radio Communications and Networks: Principles and Practice By A. M. Wyglinski, M. Nekovee, Y. T. Hou (Elsevier, December 2009) Cognitive Radio, Knobs, & Dials

21 Cognitive Radio Communications and Networks: Principles and Practice By A. M. Wyglinski, M. Nekovee, Y. T. Hou (Elsevier, December 2009) 21 Outline Motivation Software-Defined Radio Cognitive Radio Key Applications Chapter 1 Summary

22 Cognitive Radio Communications and Networks: Principles and Practice By A. M. Wyglinski, M. Nekovee, Y. T. Hou (Elsevier, December 2009) Tower of Babel Plethora of communication standards Jurisdictional differences (federal, state, provincial, municipal) Organizational differences Legacy equipment 22

23 Cognitive Radio Communications and Networks: Principles and Practice By A. M. Wyglinski, M. Nekovee, Y. T. Hou (Elsevier, December 2009) Interoperability 23

24 Cognitive Radio Communications and Networks: Principles and Practice By A. M. Wyglinski, M. Nekovee, Y. T. Hou (Elsevier, December 2009) Apparent Scarcity Measurement studies have shown that in both the time and frequency domains that spectrum is underutilized Spectrum measurement across the 900 kHz –1 GHz band (Lawrence, KS, USA) Spectrum Holes

25 Cognitive Radio Communications and Networks: Principles and Practice By A. M. Wyglinski, M. Nekovee, Y. T. Hou (Elsevier, December 2009) Dynamic Spectrum Access Spectrum measurement across the 900 kHz –1 GHz band (Lawrence, KS, USA) Fill with secondary users

26 Cognitive Radio Communications and Networks: Principles and Practice By A. M. Wyglinski, M. Nekovee, Y. T. Hou (Elsevier, December 2009) RF Spectrum Occupancy 26 Spectrum measurement across the 928 – 948 MHz band (Worcester, MA, USA)

27 Cognitive Radio Communications and Networks: Principles and Practice By A. M. Wyglinski, M. Nekovee, Y. T. Hou (Elsevier, December 2009) 27 Outline Motivation Software-Defined Radio Cognitive Radio Key Applications Chapter 1 Summary

28 Cognitive Radio Communications and Networks: Principles and Practice By A. M. Wyglinski, M. Nekovee, Y. T. Hou (Elsevier, December 2009) 28 Chapter 1 Summary Employ latest advances in microprocessor technology to enable highly flexible wireless devices Platforms possess ability for decision- making Agility allows for wide range of communications and networking operations Critical rethinking/reinvention of data transmission


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