Cognitive Radio Systems: Security & Spectrum Sharing

This assignment delves into the realm of cognitive radio systems, examining key concepts related to their operation and performance. A critical analysis of recent research papers is required, focusing specifically on two crucial aspects: the enhancement of system security within these dynamic environments and the implementation of efficient spectrum sharing strategies to maximize resource utilization. Papers covering topics like underlay and overlay communications, physical-layer security, energy harvesting, cooperative cognitive radio, opportunistic spectrum access, and directional antennas are particularly relevant. The assignment aims to synthesize the current state-of-the-art in cognitive radio research and highlight potential future directions.

Principles of Communications
Systems

Table of Contents
INTRODUCTION...........................................................................................................................1
Methodologies used in Cognitive radio system sensing.........................................................4
Function of the major parts of CR technology:......................................................................5
Function performed by Cognitive radio spectrum:................................................................6
CONCLUSION................................................................................................................................7
REFERENCES................................................................................................................................8

INTRODUCTION
The Cognitive Radio (CR) technology is major technology that is gaining e
popularity day by day. Yet, field is yet to be explored effectively to identify its full potential.
This has helped in ignificant rise in various operations which helps in better management of
different operations. CR has impacted various operations in market and has gained a significant
rise in clients or customers that has helped in better management of different operations
(Karimiand Sadough., 2017). In recent scenario, CR has seen significant rise in usage. This
technology has a very vast amount of unexploited potential that has helped in significant rise in
various operations that is needed to be taken into effective consideration to get better handling of
various operations. CR technology has a great scope of usage in wireless communication. Also,
it can be used as alternative product over highly cost radio spectrum in wireless communication
process. This helps in better growth and development of company. This report will lay effective
emphasis on various paradigms of cognitive radio technology (Elahi and et.al., 2018).
Main body
The cognitive radio technology plays a significant and effective role in better handling of
different operations. Cognitive Radio (CR) technology is form of wireless communication
medium, which allows transceiver of company to identify bands or parts of spectrum that are in
use and are free in a proper and significant manner. It helps inmoving into vacant part of
spectrum, to avoid any sort of unwanted traffic on wireless band. In recent year, software defined
radio (SDR) has increased tremendously. It helps in transceiver to identify effective geographical
location. Besides this, it also helps in proper encryption and decryption ofignals, sensing power
usage and modulation characteristics (Kebiche And et. al., 2017). The cognitive radio spectrum
has increased significantly in various operations of company and has helped in great way in
proper and significant utilisation of various spectrum that helps in t significant rise in different
operations which will help in better handling of different operations. This technology will help
in proper utilisation of various operations and segment of wireless spectrum. In recent period,
radio frequency spectrum has emerged as most valuable and natural resources. significant
increase in demand of radio frequency has led to scarcity and burden over available spectrum
that is available. Thus, this issue had led a significant rise in various operations and to effective
rise in research and development of different operations in cognitive research methodology
(Yazdani, H. and Vosoughi, A., 2017).
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Basically, re are two main cognitive radio nodes where one is full cognitive radio and or
is spectrum sensing cognitive radio. The full cognitive radio covers all parameters and spectrum
of wireless network and includes basic operations. On or hand, cognitive radio is used to
identify various operations that help in effective management of utilised as well as free bands
or channels of wireless radio spectrum. CR helps in improving of better behaviour of various
components of company that helps in significant rise in better adaptability of new bandwidths.
It involves various components like software's such as Software Defined Radio and hardware
components like mixers, modulators and amplifiers. Such technologies are used to develop
Adaptive radio which monitors and modifies its performance by itself (Li and et.al., 2017).
cognitive radio spectrum has played a significant role in major operations of company
that has impacted many vital operations of company, but major function of cognitive radio
spectrum sensing is to use same available spectrum that will help in better management of
various operations that increases productivity and profitability of business organisation. It helps
in keeping a better check on transmission of signals over wireless medium. It helps in better
utilisation of various components of wireless bandwidth and effective exploration of or usage
to improve its usability. basic Cognitive Radio Spectrum (CRS) will look after better
accommodation of different operations such as:
 Continuous spectrum sensing: It is a vital and essential tool that is used to identify
better utilisation of spectrum (Banerjee, Chakraborty and Chattopadhyay, 2018).
Basically, a cognitive radio system will use better handling of different operations that
will lead to significant rise in different operations. It uses spectrum of wireless medium
on a non-interference basis. Also, it helps in usage of spectrum for primary users.
 Monitoring alternative vacant spectrum: If primary user or system finds out that
given bandwidth is in use, system will return in order to switch onto or spectrum or
bandwidth that is vacant or not in usage. The switching takes place whenever need of
getting free spectrum arises to carry out various operations in company.
 Monitor type of transmission: most important part for a cognitive radio is that it helps
in sensing type of transmission signal or operation that is been received (Xue, Dong and
Shi, 2017). This helps transceiver to identify type of transmission used by primary user
and leads to identification of useful and futile transmission that helps in effective
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handling of various operations that help in significant rise in different operations. It also
prevents transmission of spurious signals by radio system itself.
Thus, major part of cognitive radio transfer is better handling of radio spectrum
identification that helps in better handling and effective rise in productivity and profitability of
an organisation. This will be done by using cognitive radio spectrum sensing technique that
helps in better handling of various operations that helps in significant execution of
transmission process. This technique includes 2 processes which is been taken into effective
consideration for better transmission process. two sub categories of cognitive radio spectrum
sensing are:
 Non cooperative cognitive spectrum sensing: In this type of radio transmission sensing
process, form of spectrum occurs on its own. This will help cognitive radio to configure
itself to take in consideration effective measures, to detect signal and information that are
pre-loaded in system. It helps in better utilisation of various resources i.e. hardware and
software and generate effective information or data.
 Cooperative spectrum sensing: This will include proper sensing of different operations
or radio signals that are received or transmitted through various radio devices. It takes
place under various radio spectrum services. The signals will be received by central
station from various networks and devices. The central station will look after various
bandwidths and will adjust overall cognitive radio network to suit (Hawa and et,al.,
2017.).
The cognitive radio cooperation reduces problems of interference which is caused due to
inability of a single radio to hear or get signal from primary user. It occurs due to shading by
sender.
The cognitive radio cooperation reduces the problems of interference which is caused due
to inability of a single radio to hear or get signal from the first primary user. It occurs due to the
shading by the sender. The second primary user, although will have an efficiency to receive and
hear the signal from the primary user as well as the cognitive radio system. The sending and
receiving of the cognitive system will lead to the specific handling of the various signals that will
lay a significant impact on the overall operations of the cognitive radio system (Mu, Lu and
Tugnait, 2017).
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Methodologies used in Cognitive radio system sensing
The cognitive radio spectrum will use the various techniques or methodologies to detect
the various operations and effective handling of the different operations in the company. This is
done to ensure the better sensing of the spectrum to meet the requirements of the particular
application or operation. The methodologies that are been used and implemented in the system
will help the company to ensure that it is able to avoid any sort of interference or disturbance to
other users, while analysing and maintaining the performance of itself. This will also help in
better improvement of the efficiency of the radio system of the user. Some major methodologies
that are been taken into effective consideration are:
 Spectrum sensing bandwidth: Various issues are been associated with the bandwidth
spectrum sensing process. The system will have to look after the better management of
the different operations that will help in the better looking out of the various operations.
The company will look after the single channel or operation, based on which it will
identify the alternative bandwidths that are currently in use (Yan, Zou and Zhu, 2017).
But the major issue regarding to this is that the actual reception bandwidth is needed to be
taken into consideration. The narrow bandwidths will be effectively managed by reducing
the noise floor, to improve the productivity or sensitivity of the system. This system
requires the effective wide bandwidth that helps in the better detection and transmission
on the channel.
 Transmission type sensing: This system is quite capable to identify the transmission of
the primary user effectively, for the better transfer of data in the channel or medium. But
this system is required to identify the transmission of different systems. Besides this, it
must be able to detect the transmission of the false or incorrect signals.
 Spectrum sensing accuracy: This system or methodology is used to identify the
cognitive radio spectrum sensing mechanism to detect any other signal levels accurately
to reduce the number of falsified messages or transmission. This methodology will help
in the better transfer of the different operations that will ensure the better execution of the
effective transmission process over the cognitive radio (Zappone, Matthiesen and
Jorswieck, 2017).
 Spectrum sensing timing windows: This spectrum sensing methodology will involve
the usage of the various time periods or time slots that will help in the significant
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handling of the various time slots that will help in the effective handling of the different
operations that will lead to the significant rise in the operations of the company. The
better usage of the time slot will help in the detection of the other signals too. This is
done to accommodate the signals in the frame format of overall system.
The CR based systems uses an effective measure to get the work done in the wireless
communication system. The effective use of the various software and hardware to analyse the
different operations will help in the significant operations which will help in the significant rise
in the various business functions that will support the rise in the operations that will help in the
better sensing of the underutilisation and sensing of the bandwidth spectrum (Ni and Jiang,
2017). This will help in the better providing of the effective stimuli to the end user. They help in
the better communication process and help in the significant improvement of the procedures of
the transmission of the signals through the various mediums. It provides the elaborative
introduction of the various methodologies of the signal transmission (Egan, Gorce and Cardoso,
2017). The effective management of the CR wireless communication design will include the
complete the effective redesigning of the each layer of the paradigm system. It will lead to the
effective utilisation of the different networking, hardware and software components, that will
play a very significant and crucial role in the transmission and effective handling of the various
operations that will help in the significant handling of the different functions that will help in the
better management of the productivity and profitability by using IEEE 802.22 band to execute
the functionality.
Function of the major parts of CR technology:
The CR will play a significant role in the execution and management of the different
operation that will help in the effective handling of the various business operations which will
help in the rise of productivity and profitability of the company. It will consist of the different
operations that will help in the significant functions which will help in the better execution of the
various operations related to the transmission process (Afana., Mahady and Ikki , 2017). This
consists of the various parts of the CR system, either individually or in a group or combination,
will work in the significant manner to gain better productivity and profitability. Some major CR
components are as follows:
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 Licensed band Cognitive Radio: It is used to analyse and meet the needs and
requirements of the bands allotted to the licensed user. It used the wireless regional area
network to transmit the unused TV channels also known as the white spaces.
 Unlicensed band cognitive radio: It is the method and technology which uses only the
unused, unlicensed part of the spectrum. It focuses on the coexistence for the 802.22 and
Bluetooth technology in a very effective way.
 Spectrum mobility: This method is used to by the primary user and the receiver to take
into consideration the effective and significant measure to move within the various
bandwidth of the wireless spectrum. This will help the terminals to meet the best
availability of the band and leads to the better and seamless communication requirements
while operating in the spectrum.
 Spectrum sharing: These methods involves the better sharing of the various brands that
will lead to the better handling of the various components to utilise the part of band by
the licensed user (Lei and et.al., 2017).
 Sensing based spectrum sharing: It gives rise to the sensing based sharing of the
cognitive radio frequency. The licensed users will look after the better utilisation of the
bandwidth that helps in the better identification of the signal. If the licensed users are not
using the bandwidth, cognitive radio shares this bands for the transmission.
 Database enabled Spectrum sharing: This involves the better utilisation of the white
space database, which is available in the TV signals. It involves the better utilisation of
the various algorithms which helps in the effective handling of the interference that takes
place. It helps in the better utilisation of the various resources and bandwidths of the
spectrum. If the destructive interference is identified, the cognitive radio user is denied
access of the spectrum in order to safeguard the devices and data.
Function performed by Cognitive radio spectrum:
The cognitive radio spectrum will help in the better handling of the various operations
that will help in the better functioning of the transmission components. This will help in the
improvement of the various operations that will increase in efficiency this will help in the
effective handling of the different operations which will help in the effective handling of the
different operations. Some major functions that are been performed are as follows:
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 Power control: The CR system will use the effective handling of the different
operational functions to maximise the capacity of secondary user with interference in
order to protect the primary user of the bandwidths.
 Spectrum sensing: Detection of the unused spectrum or bandwidths and sharing them in
the system, without any harmful interference will be looked after by the CR user. It is the
most effective way to detect empty spectrum.
 Wideband sensing: This will help in the better management of the various operation
which will be used by the CR system to identify and measure bandwidths in MHz or
GHz. It is used to send and receive high resolution data using high transmission
techniques (Afana., Mahady and Ikki , 2017).
 Spectrum management: This process will involve the better utilisation of the various
measures that will lead to the bands to provide high quality of services. It involves the
processes like Spectrum analysis and Spectrum decision which help in the betetr selection
of bandwidth.
CONCLUSION
Thus, it can be said that the Cognitive Radio (CR) plays a very important and crucial role
in the effective handling of the different operations that will lead to the significant rise in the
various operations which will help in improving the productivity. This report laid the emphasis
on various paradigms that supports the better utilisation of the various bandwidth and the
effective functions that are been performed by them. Various types of the processes used by CR
user to get the productivity and better utilisation of the bandwidths is been discussed. Besides
this, various methods of the CR system sensing are been taken into effective consideration for
discussion.
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REFERENCES
Books and journals
Lei, H. and et.al., 2017. Secrecy outage performance of transmit antenna selection for MIMO
underlay cognitive radio systems over Nakagami-$ m $ channels. IEEE Transactions on
Vehicular Technology. 66(3). pp.2237-2250.
Afana, A., Mahady, I.A. and Ikki, S., 2017. Quadrature spatial modulation in MIMO cognitive
radio systems with imperfect channel estimation and limited feedback. IEEE
Transactions on Communications. 65(3). pp.981-991.
Egan, M., Gorce, J.M. and Cardoso, L., 2017, July. Fast Initialization of Cognitive Radio
Systems. In IEEE International Workshop on Signal Processing Advances in Wireless
Communications.
Ni, C. and Jiang, T., 2017. Minimizing the Error Vector Magnitude With Constrained Cubic
Metric and Spectral Sidelobe in NC-OFDM-Based Cognitive Radio Systems. IEEE
Transactions on Vehicular Technology. 66(1). pp.358-363.
Zappone, A., Matthiesen, B. and Jorswieck, E.A., 2017. Energy efficiency in MIMO underlay
and overlay device-to-device communications and cognitive radio systems. IEEE
Transactions on Signal Processing. 65(4). pp.1026-1041.
Yan, P., Zou, Y. and Zhu, J., 2017. Energy-Aware Multiuser Scheduling for Physical-Layer
Security in Energy-Harvesting Underlay Cognitive Radio Systems. IEEE Transactions
on Vehicular Technology.
Mu, H., Lu, P. and Tugnait, J.K., 2017. Secure degrees of freedom in cooperative K-helper
MIMO cognitive radio systems. Physical Communication. 25. pp.598-609.
Hawa, M and et,al., 2017. Distributed opportunistic spectrum sharing in cognitive radio
networks. international journal of communication systems.30(7).
Xue, T., Dong, X. and Shi, Y., 2017. Resource-Allocation Strategy for Multiuser Cognitive
Radio Systems: Location-Aware Spectrum Access. IEEE Transactions on Vehicular
Technology. 66(1). pp.884-889.
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Banerjee, J.S., Chakraborty, A. and Chattopadhyay, A., 2018. Relay node selection using
analytical hierarchy process (AHP) for secondary transmission in multi-user cooperative
cognitive radio systems. In Advances in Electronics, Communication and Computing (pp.
745-754). Springer, Singapore.
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1-6). IEEE.
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antennas and imperfect spectrum sensing. In Acoustics, Speech and Signal Processing
(ICASSP), 2017 IEEE International Conference on(pp. 3589-3593). IEEE.
Kebiche, D.E. And et. al., 2017, October. UFMC-based wideband spectrum sensing for cognitive
radio systems in non-Gaussian noise. In Personal, Indoor, and Mobile Radio
Communications (PIMRC), 2017 IEEE 28th Annual International Symposium on (pp. 1-
7). IEEE.
Elahi, A. andf et.al., 2018, January. Efficient sidelobe reduction for OFDM based cognitive radio
systems. In Applied Sciences and Technology (IBCAST), 2018 15th International
Bhurban Conference on(pp. 831-834). IEEE.
Karimi, M. and Sadough, S.M.S., 2017. Efficient Transmission Strategy for Cognitive Radio
Systems Under Primary User Emulation Attack. IEEE Systems Journal.
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