overview of cognitive radio systems - etsi07.12.2011 prof. dr.-ing. rüdiger kays | communication...
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Prof. Dr.-Ing. Rüdiger Kays | Communication Technology Institute
Workshop Cognitive PMSE Systems
Overview of Cognitive Radio SystemsProf. Dr.-Ing. Ruediger Kays
Communication Technology Institute
07.12.2011CogRadio_Kays.ppt Slide 2Prof. Dr.-Ing. Rüdiger Kays | Communication Technology Institute
Contents
Overview of Cognitive Radio Systems
Motivation
Basic Concepts
Application Scenarios
Outlook
07.12.2011CogRadio_Kays.ppt Slide 3Prof. Dr.-Ing. Rüdiger Kays | Communication Technology Institute
Contents
Overview of Cognitive Radio Systems
Motivation
Basic Concepts
Application Scenarios
Outlook
07.12.2011CogRadio_Kays.ppt Slide 4Prof. Dr.-Ing. Rüdiger Kays | Communication Technology Institute
Motivation (1)
Radio spectrum is scarce ...
See e.g. German "Frequenznutzungsplan", a document of 674 pages...
Source: www.bundesnetzagentur.de, "Frequenznutzungsplan zum Herunterladen", Stand 31.08.2011, Download 15.11.2011
07.12.2011CogRadio_Kays.ppt Slide 5Prof. Dr.-Ing. Rüdiger Kays | Communication Technology Institute
Motivation (2)
Radio spectrum is expensive ...
Price of UMTS licenses in Germany in 2000 (120 MHz @ 2 GHz, 20 years): 50.8 billion €
Price of licenses for mobile communication in Germany in 2010 (60 MHz @ 0.8 GHz): 2.96 billion €
07.12.2011CogRadio_Kays.ppt Slide 6Prof. Dr.-Ing. Rüdiger Kays | Communication Technology Institute
The Race for Efficiency
Efficiency is extremely important!
The history of communication efficiency:
1948: C. E. Shannon: Information Theory
1950s/1960s Algebraic Channel Coding
1970s/1980s Convolutional Codes, Concatenated Codes
Early 1990s The "Turbo Revolution"
Late 1990s: MIMO Systems: Multiple Antennas ~ Multiple Transmission Capacity
07.12.2011CogRadio_Kays.ppt Slide 7Prof. Dr.-Ing. Rüdiger Kays | Communication Technology Institute
Motivation (3)
But in reality, in any location most of the radio spectrum is free!
Measurement of power density, LS KT,TU Dortmund, 18.11.2011
07.12.2011CogRadio_Kays.ppt Slide 8Prof. Dr.-Ing. Rüdiger Kays | Communication Technology Institute
Contents
Overview of Cognitive Radio Systems
Motivation
Basic Concepts
Application Scenarios
Outlook
07.12.2011CogRadio_Kays.ppt Slide 9Prof. Dr.-Ing. Rüdiger Kays | Communication Technology Institute
Definition Cognitive Radio
Cognitive Radio System (ITU Definition):
A radio system employing technology that allows the system to obtain knowledge of its operational and geographical environment, established policies and its internal state; to dynamically and autonomously adjust its operational parameters and protocols according to its obtained knowledge in order to achieve predefined objectives; and to learn from the results obtained.
Definition in Rec. ITU-R SM.2152, 2009
07.12.2011CogRadio_Kays.ppt Slide 10Prof. Dr.-Ing. Rüdiger Kays | Communication Technology Institute
Some related definitions...
Software Defined Radio:
A transmitter/receiver employing a universal hardware structure which can be adapted to apply different radio transmission modes (modulation, channel coding, transmission frequency) by software
SDRs are useful tools to implement cognitive radio!
RFFrontend
AD
DA
Signal Processor
Control/Software
Data out
Data in
Antenna
07.12.2011CogRadio_Kays.ppt Slide 11Prof. Dr.-Ing. Rüdiger Kays | Communication Technology Institute
Some related definitions...
White Spaces:
„White spaces“ are channels within the licenced TV spectrum that are not used for TV services at a given location
Especially the TV UHFbands (470 – 790 MHz)are an interestingresource!
Measurement of power density, LS KT,TU Dortmund, 18.11.2011
EBU: „10 things you need to know about ...“, September 2011
07.12.2011CogRadio_Kays.ppt Slide 12Prof. Dr.-Ing. Rüdiger Kays | Communication Technology Institute
Technical Concept
Cognitive Radio ...
...allows reuse of spectrum in white spaces
...supports dynamic spectrum access
...enables efficient transmission
...can make wireless transmission arbitrarily robust
07.12.2011CogRadio_Kays.ppt Slide 13Prof. Dr.-Ing. Rüdiger Kays | Communication Technology Institute
Technical Concept
Cognitive Radio: Often means dynamic spectrumallocation, e.g. reuse of spectrum allocated to incumbent users/applications
Where does the C.R. information come from?
Spectrum sensing
Specific signalling
Data bank
By the way: A certain reuse of spectrum can also be achieved by UWB technology
07.12.2011CogRadio_Kays.ppt Slide 14Prof. Dr.-Ing. Rüdiger Kays | Communication Technology Institute
How to become cognitive (1)
Spectrum Sensing
Pros:
Detection of incumbent users without the need for infrastructure – a backward compatible solution!
Detection also of other cognitive systems – self organization of spectrum reusers possible
Cons:
Implementation effort for spectrum scanner
Reliable detection of incumbents or other users of spectrum not possible in certain constellations
Detector
07.12.2011CogRadio_Kays.ppt Slide 15Prof. Dr.-Ing. Rüdiger Kays | Communication Technology Institute
Problems of Spectrum Scanning
07.12.2011CogRadio_Kays.ppt Slide 16Prof. Dr.-Ing. Rüdiger Kays | Communication Technology Institute
Problems of Spectrum Scanning
cognitiveradio
incumbent
07.12.2011CogRadio_Kays.ppt Slide 17Prof. Dr.-Ing. Rüdiger Kays | Communication Technology Institute
Problems of Spectrum Scanning
Where is GPS???
07.12.2011CogRadio_Kays.ppt Slide 18Prof. Dr.-Ing. Rüdiger Kays | Communication Technology Institute
How to become cognitive (2)
Signalling of incumbent usage
Pros:
Adaptive solution possible
Helps to support self organisation of cognitive radios
Cons:
Signals have to be generated
Scanning required
Additional transmission effort
No backwards compatibility
07.12.2011CogRadio_Kays.ppt Slide 19Prof. Dr.-Ing. Rüdiger Kays | Communication Technology Institute
How to become cognitive (3)
Use of a data bank
Pros:
Dynamic spectrum effort for spectrum scanner avoided
Can supply reliable information about incumbent users
Cons:
Detailed information for each location has to be provided
Cognitive radio nodes need localisation
Information has to be distributed (e.g. by „cognitive channel“)
No support of cognitive network organisation
07.12.2011CogRadio_Kays.ppt Slide 20Prof. Dr.-Ing. Rüdiger Kays | Communication Technology Institute
Solution
Universal solution for cognitive radio systems:Combine concepts
Different information sources should be combined, depending on application and scenario
07.12.2011CogRadio_Kays.ppt Slide 21Prof. Dr.-Ing. Rüdiger Kays | Communication Technology Institute
"Ether"
Cognitive Radio Node
Universal Cognitive Radio System
AdjustableRadio
Transceiver** Adjustment of: frequency transmission power modulation scheme and FEC medium access parameters
Data
InternalData Base
SpectrumScanner
LocalCognitive
EnginePolicy andEtiquette
Cognit. Ch.Transceiver
C.R.S. DistributedData Base
07.12.2011CogRadio_Kays.ppt Slide 22Prof. Dr.-Ing. Rüdiger Kays | Communication Technology Institute
Contents
Overview of Cognitive Radio Systems
Motivation
Basic Concepts
Application Scenarios
Outlook
07.12.2011CogRadio_Kays.ppt Slide 23Prof. Dr.-Ing. Rüdiger Kays | Communication Technology Institute
Hierarchy
Dynamic Spectrum Usage Hierarchy
Incumbent Useralways has right of way…
Cognitive RadioSystem #1
give right of wayto incumbents…
Cognitive RadioSystem #2
Cognitive RadioSystem #n
coordination?...
07.12.2011CogRadio_Kays.ppt Slide 24Prof. Dr.-Ing. Rüdiger Kays | Communication Technology Institute
Application Scenarios (1)
DVB-T@f1
DVB-T@f1
SFN 1
DVB-T@f1
DVB-T@f1
SFN 2
Cognitive Radio Systemin White Space
07.12.2011CogRadio_Kays.ppt Slide 25Prof. Dr.-Ing. Rüdiger Kays | Communication Technology Institute
Application Scenarios (2)
C-PMSE
07.12.2011CogRadio_Kays.ppt Slide 26Prof. Dr.-Ing. Rüdiger Kays | Communication Technology Institute
Application Scenarios (3)
....
....
Mobile Network
07.12.2011CogRadio_Kays.ppt Slide 27Prof. Dr.-Ing. Rüdiger Kays | Communication Technology Institute
Application Scenarios (4)
HomeGateway
Sat-Receiver
LocalServer
CognitiveMedia Network 2
CognitiveMedia Network 1
Cognitive Control Network
CognitiveHome Network
07.12.2011CogRadio_Kays.ppt Slide 28Prof. Dr.-Ing. Rüdiger Kays | Communication Technology Institute
Contents
Overview of Cognitive Radio Systems
Motivation
Basic Concepts
Application Scenarios
Outlook
07.12.2011CogRadio_Kays.ppt Slide 29Prof. Dr.-Ing. Rüdiger Kays | Communication Technology Institute
Current Situation
European and international standardization:
ITU-R, e.g. WRC-2012
ETSI (e.g. TC Reconfigurable Radio Systems)
IEEE (SCC 41, P1900, IEEE 802,...)
Research projects
~ 20 projects in EU FP 7, e.g. QoSMOS,...
German national projects, e.g. C-PMSE, research program „Kognitive drahtlose Kommunikationssysteme“,...
Cognitive Radio is a hot topic in research, development and standardization
07.12.2011CogRadio_Kays.ppt Slide 30Prof. Dr.-Ing. Rüdiger Kays | Communication Technology Institute
Outlook
Basic idea of cognitive radio is not new
Basic concepts are known, at least in principle
Outlook
The paradigm of fixed frequency assignments has to be replaced by dynamic spectrum access to achieve
optimal usage of wireless ressources!
BUT:Complexity of wireless transmission environment
requires a lot of research on practical solutions for different scenarios!
Prof. Dr.-Ing. Rüdiger Kays | Communication Technology Institute
Thank You for Your Attention!