Development of a Database-Assisted Spectrum Access Scheme for Cognitive Radio Utilizing Radar Bands

This report discusses the development of a database-assisted spectrum access scheme for cognitive radio utilizing radar bands. It includes project information, objectives, work area, responsibilities, distinctive activities, engineering knowledge and skills applied, technical difficulties and solutions, plan for creative and innovative work, collaborative work, project review, and project results.

COMPETENCY
DEMONSTRATION REPORT
Career Episode 2

CE 3.1 Project Information
Name of the project: Development of a Database-Assisted Spectrum Access Scheme for
Cognitive Radio Utilizing Radar Bands
Location of the project: [Malaysia]
Project Duration: [2016]
Organization: International Islamic University Malaysia
Role and Designation during the time: Communication Engineer
Supervisor: Elsheikh Mohamed Ahmed Elsheikh
CE 3.2 Project Background
CE 3.2.1 Characteristics of the project
I considered the scarcity of the spectrum in the field of the wireless communication
system as the concerning sector that could be eliminated through my approach. I introduced the
Cognitive Radio idea assuring the efficient application of the spectrum. The evaluation of the
radio frequency resulted in being informed that occupancy of the radar bands is very low (2-6
GHz) and under 5% approximately throughout the time span of a single day. I combined the
technique of the dynamic frequency selection and energy detector-based sensing scheme with
database scheme. I compared and analyzed the performance of the spectrum developed using
these techniques separately. I mathematically modeled the proposed schemes and implemented
the simulation in the MATLAB. The delivered analysis results better detection performance

achievement in addition to the higher SNR values. I also found that the performance detection is
higher in the Nakagami channel as compared with the Rayleigh channel as the fading severity
comparatively high as compared to that of the Rayleigh channel.
CE 3.2.2 Objectives developed for the project
The objective for this cmpetency was to develop the Hybrid Spectrum Access Technique
through the application of both the temporal and spatial spectrum opportunities. I used the
technique of combining the spectrum sensing with the geo-location database scheme. The
performance of the proposed method is compared and analyzed with the different techniques
separately. The objectives can be listed as following:
 To examine the energy detectors’ detection performance
 To establish the model that combines the sensing database and scheme.
 To examine the efficiency and performance of the model that was proposed.
CE 3.2.3 My particular work area
Considering the leadership attribute, I was successful in establishing the scope and
objectives of the project those were strictly followed for meeting the results of the proposed
approach. I also developed a feasible methodology that I followed till the end of my research and
gained positive outcome through reaching at the conclusion. I also developed and used the
energy detection model under the fading channels and the AWGN channels. In the experimental
sector, I also analysed the search radar noise limited model and determined the minimum
required SNR. Thereafter, I moved towards the analysis of the interreference limited radar
including then multiple secondary user and single secondary user. I developed the following
Energy Detection Model for the delivery of the project:

CE 3.2.4 My responsibilities throughout the project
I was responsible for delivering all the theoretical and practical work in this experimental
analysis. I had to make sure that the developed objectives met through the successful and proper
delivery of the entire project. I was responsible for establishing regular communication with the
supervisor and co supervisor for assuring that the project moves in a single direction. It was my
responsibility to make sure that the literature review being made is based on the analysis of the
peer-reviewed journals and the later experiments are related to the same context with my
innovative additions. I considered the cost of the project as a major aspect considering its mass

application among the targeted customers and hence, I managed to keep the budget of the project
low as much possible.
CE 3.3 Distinctive Activity
CE 3.3.1 Comprehending the theory of the project
In the coexistence approaches of all the primary secondary users, Interference to the
primary system from secondary system is throughout the permissible range. We also analyzed
the first interference to Secondary devices of Radarfrom to the Radar and the analysis has been
done for estimating the distance any secondary uses are restricted to perform the transmission. I
analyzed the performance and influence of the radar pulse signals those are of high-power over
the Wi-Fi network’s throughput. Firstly, I simulated the energy detector’s performance
thereafter, I also analyzed them in manner to record and collect results or the elements those are
capable of influencing the detector’s performance. The SNR’s effect on the probability of the
performance under the various detection platforms of the false alarm. In addition,
CE 3.3.2 Engineering knowledge and skills applied in the project
I used my theoretical knowledge gained during my course and performed the various
mathematical calculations for calculating the various parameters those were necessary for the
simulation and result finding. I used these calculations:
Considering the collected data, I extended my further calculation for identifying the
achievable data rate for 802.11n specifications as:
SNR Data Rate (Mbps)
6.5 13
4.5 6.5

8 19.5
13.5 39
10.5 26
17.5 52
21.5 65
19.5 58.5
I operated different channel model considering the noise as the major impacting factor
and successfully calculated the energy under different channels. I detected the energy under
AWGN channel, fading channels, and identified the factors for detecting radar noise limited
model. I performed the researches and developed the design those can alternatively contribute in
the development of the high-gain antennas those could be applied for mitigating the existing
threats and risks in the antenna designs. The energy detector performance was analyzed with the
following graph:

Figure: SNR Effect on AWGN detection probability

Figure: SNR Effect for the false alarms

Figure: Receiver Operating Characteristic (ROC) Curves (Pd V/s Pfa)

Figure: (Pmd V/S Pfa)
CE 3.3.3 Technical difficulties and solutions
The performance of the detector can be influenced by many parameters and so, I
performed the simulation on the energy detector that helped in identifying the parameters those
are capable of influencing the performance of this detector. We studied the detector’s
performance under AWGN for various SNR values. Additionally, we also discussed the effect of
the detected pulses’ number on detection performance.

CE 3.3.4 Plan to produce creative and innovative work
I proposed an interference detection algorithm and run the simulations that was used in
further calculations and the result findings. In addition to these simulations, I made sure that the
other factors should be analysed and hence, I analysed and simulated the scenarios of
interference limited and the protection distance under the noise limited. The evidence was found
that the distance of the protection reduces expressively when any information is possessed by the
secondary user regarding radar rotation and antenna pattern. It is because of the situation, when
the secondary user was not having the information of the radar rotation, it needs to be assumed
that any persistent determined gain; hence, the distance of separation would be constant. Same as
this, throughput enhances with information about the rotation of the Radar and its pattern of
antenna. Considering different side of the project, exploitation of the radar rotation information
the variations in the gain of the Radar can be found consequently.
CE 3.3.5 Collaborative work
The project would have never been completed without the guidance of the supervisor that
helped me through providing the better guidance and clarifications on the ways through which I
delivered the project successfully. I built a better relationship with the supervisor and he always
responded me in better way whenever I needed some directions. Other than the supervisor, co-
supervisor also helped me in understanding the valuable suggestions in the same work.

CE 3.4 Project Review
CE 3.4.1 Project Results
I successfully analysed the detection performance of energy detector simulation. I
analyzed the different detection performances and it was observed that performance under
AWGN channel was comparatively good as that of the fading channels including Nakagami and
Rayleigh. In addition to this result; finding that the Rayleigh fading channel detection
performance was not effective as compared to that of the Nakagami because of the Rayleigh
environments’ high fading severity however, it was also identified that the fading severity has
low parameters in the Nakagami parameter, the excessive parameter leads to the low fading
effect severity in throughout the radar rotation. Moreover, the further attempts being delivered
resulted in the output that the radar searching protection distance can be found through operating
the WiFi network at 2.7-2.9 GHz frequency as it was allocated for the radars searching.
CE 3.4.2 My involvement in this project
Implementing a Cognitive radio, (CR) will lead to development of a smart radio that
allows configuration dynamically. With the help of co-located transmitter and receiver, one can
understand and sense the free communication channel and the channel already occupied. The aim
of this project was to provide an access technique using spectrum that uses opportunities of both
temporal and spatial spectrum. In this method, the sensing scheme based on energy detector and
dynamic selection frequency are combined for achieving the database scheme. However, the
technique can be analyzed and compared based on methods performance. While detecting the
energy performance it is analyzed that better performance was achieved by using SNR values.