Intelligent radio that prevents interference. Just a concept right now that is evolving

1. SOME SECURITY ISSUES

2. OVERVIEW
 Introduction
 What is Cognitive Radio?
 Spectrum Sensing
 Primary User Emulation
 Simulation & Results

3. INTRODUCTION
 Evolution of numerous wireless applications.
 Limited Public Bandwidth or Spectrum
 Inefficient use of Licensed Spectrum
 What if one could use the licensed spectrum when no
primary users are using it?

5. WHAT IS COGNITIVE RADIO?
 Intelligent Radio.
 Senses Environment and Spectrum(Cognitive
capability).
 Analyzes it(Self-organized capability).
 Adapts to it(Reconfigurable capability).
 Learns from the results.

6. General Architecture of Cognitive Radio

7. SPECTRUM SENSING
 Dynamic Spectrum Access (DSA)
 Distributed Spectrum Sensing (DSS)
 Common Control Channel (CCC)

9. SPECTRUM SENSING
 Dynamic Spectrum Access (DSA)
 Distributed Spectrum Sensing (DSS)
 Common Control Channel (CCC)

10. SPECTRUM SENSING
 Dynamic Spectrum Access (DSA)
 Distributed Spectrum Sensing (DSS)
 Common Control Channel (CCC)

11. CCC
Cooperation
Optimization

12. SPECTRUM SENSING TECHNIQUES
 Matched Filter
 Cyclo-Stationary Feature
 Energy Detection

13. SPECTRUM SENSING TECHNIQUES
 Matched Filter
 Cyclo-Stationary Feature
 Energy Detection

14. SPECTRUM SENSING TECHNIQUES
 Matched Filter
 Cyclo-Stationary Feature
 Energy Detection

15. PRIMARY USER EMULATION
 Idle spectrum can be used by secondary users
without causing disturbance to the primary user.
 But these secondary users must co-operate and use
the spectrum fairly.
 Some secondary users prevent others from using this
idle spectrum by transmitting unrecognizable signals.
 i.e. they emulate (imitate) the primary users and
hence prevent secondary users from utilizing it.
 They are of two types:
 Selfish PUE attackers
 Malicious PUE attackers

16. SYSTEM MODEL FOR CRNs

17. Received power due to
Primary Transmitter,
Pr_p
PDF of Pr_p
Received power due to
Malicious users, Pr_m
PDF of Pr_m

18. SIMULATION & RESULTS
 The following slides contain the simulated
results of the PDFs of signals received by the
secondary receiver due to primary
transmitter and malicious users.

22. SYSTEM MODEL FOR CRNs

23. SYSTEM MODEL ALTERATION
 As it can be seen, the results of the previous
system model are not desirable.
 So, another system model is presented to
counteract the PUE.

24. PROPOSED MODEL