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 covers the project background, objectives, distinctive activities, engineering knowledge and skills applied, identified issues and their solutions, and project results. The project was conducted at the International Islamic University Malaysia.

COMPETENCY
DEMONSTRATION REPORT
Career Episode 3

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

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 developed the
technique of spectrum access that uses both temporal and spatial spectrum opportunities. 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 has been more high in Rayleigh channel.
CE 3.2.2 Objectives developed for the project
The major objectives for the development of this research 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 area of work
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 project. As a
learner, I performed the literature review, secondary data analysis that was very helpful and
effective in clearing the concepts the direction that need to be followed in manner to meet the
necessary objectives and goals of the project. 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 li9mioted
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.

CE 3.2.4 Project Group
CE 3.2.5 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 must be within the permissible ranges. WE also analyzed
the first interference to Radarfrom Secondary devices to Radar has been analyzed in order to
estimate the distance in which the Secondary users are not allowed to transmit within.
Furthermore, the interference from Radar to Secondary devices has been discussed to assess its
effect on achievable throughput as a function of distance to Radar. 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:
I found the angle definitions:
Very High-Gain
(G>48dBi)
High-Gain
(22>G<48dBi)
Medium-Gain
(10<G<22dBi)

Equations for Very High-Gain Antennas (G>48dBi):
Angular Interval (Degrees) Gain (dBi)
0 to M
M to R
R to B
B to
Equations for High-Gain Antennas (22>G<48dBi):
Angular Interval(Degrees) Gain(dBi)

0 to M
M to R
R to B
B to
Equations for Medium -Gain Antennas (10<G<22dBi):
Angular Interval
(Degrees)
Gain
(dBi)
0 to M
M to R
R to B

B to
Finally, considering these 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
CE 3.3.3 Identified issues and their 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 protection distance
under noise limited, interference limited scenarios. It was discovered that, the protection distance
significantly reduces when the secondary user has information about the Radar rotation as well

as Radar antenna pattern. This is due to the fact that, when secondary user has no information
about Radar rotation, it has to assume a constant maximum gain; therefore, the separation
distance will be constant. On the other hand, when information about Radar rotation is utilized,
the Radar gain will vary accordingly. Similarly, the throughput improves with the information
about Radar rotation and its antenna pattern.
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 found
that the detection performance under AWGN channel was better while compared to the fading
channels such as Nakagami and Rayleigh. In addition to this result; finding that the Rayleigh
fading channel detection performance is worse 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 m, the higher this parameter the less
severe is the fading effect. Furthermore, some analysis has been done on protection distance of a
search Radar and the resulting Wi-Fi throughput when a Wi-Fi network operates in 2.7-2.9GHz
frequency band allocated for search Radars.

CE 3.4.2 My contribution to work
Implementing a Cognitive radio, (CR) will lead to development of a smart radio that
allows configuration dynamically. This is a form of wireless communication. 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 dissertation is to develop an access
technique-using spectrum that uses opportunities of both spatial and temporal spectrum. In this
technique, the energy detector based sensing scheme 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.