52 research outputs found
An Innovative Signal Detection Algorithm in Facilitating the Cognitive Radio Functionality for Wireless Regional Area Network Using Singular Value Decomposition
This thesis introduces an innovative signal detector algorithm in facilitating the
cognitive radio functionality for the new IEEE 802.22 Wireless Regional Area
Networks (WRAN) standard. It is a signal detector based on a Singular Value
Decomposition (SVD) technique that utilizes the eigenvalue of a received signal. The
research started with a review of the current spectrum sensing methods which the
research classifies as the specific, semiblind or blind signal detector. A blind signal detector, which is known as eigenvalue based detection, was found to be the most
desired detector for its detection capabilities, time of execution, and zero a-priori knowledge. The detection algorithm was developed analytically by applying the Signal Detection Theory (SDT) and the Random Matrix Theory (RMT). It was then simulated
using Matlab® to test its performance and compared with similar eigenvalue based
signal detector. There are several techniques in finding eigenvalues. However, this
research considered two techniques known as eigenvalue decomposition (EVD) and
SVD. The research tested the algorithm with a randomly generated signal, simulated
Digital Video Broadcasting-Terrestrial (DVB-T) standard and real captured digital
television signals based on the Advanced Television Systems Committee (ATSC)
standard. The SVD based signal detector was found to be more efficient in detecting
signals without knowing the properties of the transmitted signal. The algorithm is
suitable for the blind spectrum sensing where the properties of the signal to be detected
are unknown. This is also the advantage of the algorithm since any signal would
interfere and subsequently affect the quality of service (QoS) of the IEEE 802.22
connection. Furthermore, the algorithm performed better in the low signal-to-noise
ratio (SNR) environment. In order to use the algorithm effectively, users need to
balance between detection accuracy and execution time. It was found that a higher
number of samples would lead to more accurate detection, but will take longer time.
In contrary, fewer numbers of samples used would result in less accuracy, but faster
execution time. The contributions of this thesis are expected to assist the IEEE
802.22 Standard Working Group, regulatory bodies, network operators and end-users
in bringing broadband access to the rural areas
Smart Cards And The Fingerprint : A Proposed Framework For The Automatic Teller Machine (ATM) System
The need to control access to certain information and resources has been taken seriously nowadays due to fraud and other threats to current security systems. This
research believes that no single security method, algorithm, key or procedure is entirely secure. Hence, a combination of multiple security components is mandatory
to provide a high level of protection against fraud and other threats. This research combines three security components, which are, the smart card, fingerprint
recognition and cryptography. It looks into the vulnerabilities of magnetic-stripe cards and personal identification numbers (PIN) or passwords widely used in
systems today. As a result, the research proposed a framework for user identification and authentication in automatic teller machine (ATM) systems using fingerprints
and smart cards as opposed to the PIN and magnetic-stripe cards. The cryptography is also implemented to further secure the data stored on the smart card. This robust
method of user identification and authentication would hopefully reduce the vulnerabilities of ATM in the future
Performance Comparison of Downlink Packet Scheduling Algorithms in LTE Network
Long Term Evolution (LTE) was introduced by the Third-Generation Partnership Project (3GPP) and is considered as the latest step towards the fourth generation of radio technology. This paper investigates the performance of well-known packet scheduling algorithms such as Proportion Fair (PF), Maximum- Largest Weighted Delay First (M-LWDF), Exponential Proportion Fair (EXP/PF), Frame Level Scheduler (FLS), Exponential rule (EXP rule), and Logarithmic rule (LOG Rule) in terms of delay, throughput, and packet loss ratio (PLR) by using the LTE-Sim open source simulator. Different traffic types are used, and Simulation results show that in video traffic, FLS and EXP algorithms provide a higher system throughput compared to other algorithms while keeping the delay and packet loss ratio small. However, in the case of best-effort traffic, results show a high delay and PLR with low throughput. The main contribution of this paper is to determine the appropriate downlink scheduling algorithm for VOIP, video, and best-effort traffics in 3GPP LTE
Signal detection algorithm for cognitive radio using singular value decomposition
This paper highlights an algorithm for detecting the presence of wireless signal using the Singular Value Decomposition (SVD) technique.We simulated the algorithm to detect common digital signals in wireless communication to test the performance of the signal detector.The SVD-based signal detector was found to be more efficient in detecting a signal without knowing the properties of the transmitted signal.The performance of the algorithm is better compared to the favorable energy detection.The algorithm is suitable for blind spectrum sensing where the properties of the signal to be detected are unknown.This is also the advantage of the algorithm since any signal would interfere and subsequently affect the quality of service (QoS) of the IEEE 802.22 connection.Furthermore, the algorithm performed better in the low signalto-noise ratio (SNR) environment
An energy-efficient MAC protocol to conserve energy in wireless sensor networks
Wireless Sensor Network (WSN) nodes are widely
used in various sectors nowadays. WSN nodes
experience a lot of problems that impact on battery life for sensor node such as, overhearing, collision,hidden node, idle listening, schedule drifts, and high latency. Moreover, WSN nodes are strongly dependent on its limited battery power, and replenishing it again is difficult as nodes are deployed in an ad-hoc manner.Energy consumption is the most important factor to determine the life of a sensor network because
usually sensor nodes are driven by low battery
resources. An approach to conserve energy in WSN
nodes is to carefully design its Medium Access
Control (MAC) protocol. Several previous work
has been carried out to mitigate many problems that impact on battery life for sensor node such as overhearing, collision, and hidden node. This paper attempts to design Energy-Efficient MAC (EEMAC), a hybrid energy-efficient protocol to
address the energy issues that are related to WSNs
nodes.This protocol aims to reduce idle listening
times as well as lowering the latency time thus
reducing the energy consumption.The proposed protocol has been developed and analyzed using the
ns-2 Simulator.A mathematical model was used to
prove the efficiency of the proposed protocol. We
have compared our proposed EE-MAC protocol
with the existing contention-based IEEE 802.11
PSM protocol.The simulation results illustrate that the EE-MAC has achieved better energy
conservation than the IEEE 802.11 PSM protocol
The performance of DCCP TCP-like with initial slow-start threshold manipulation
This paper investigates the performance of the
implementation of modified initial slow-start threshold size in Datagram Congestion Control Protocol (DCCP) TCP-like (CCID-2) over long delay
link network.TCP-like is one of a congestion control mechanism for DCCP which is suitable for the delivery of multimedia data with abrupt changes during the transmission. The scenario is set for long delay link network,where the impact of the modified slow-start threshold value in TCP-like is significant.As a result, we managed to reduce the time required to obtain the maximum throughput in TCP-like during in the slow-start phase.The result shows that with the correct manipulation of initial slow-start threshold
size for TCP-like, it will give a significant improvement to TCP-like performance over long delay link where the maximum throughput during
the slow-start phase can be achieved faster
Analysis of internet traffic in educational network based on users' preferences
The demand for Internet services and network resources in Educational networks are increasing rapidly.Specifically, the revolution of web 2.0 "also referred to as the Read-Write Web" has changed the way of information exchange and distribution. Although web 2.0 has gained attraction in all sectors of the education industry, but it results in high-traffic loads on networks which often leads to the Internet users" dissatisfaction.Therefore, analyzing Internet traffic becomes an urgent need to provide high-quality service, monitoring bandwidth usage.In this study, we focus on analyzing the Internet traffic in Universiti Utara Malaysia (UUM) main campus. We performed measurement analysis form the application level characteristics based on users' preferences.A total of three methodological steps are carried out to meet the objective of this study namely data collection, data analysis and data presentation.The finding shows that social networks are the most web applications visited in UUM.These findings lead to facilitate the enhancement of Educational network performance and Internet bandwidth strategies
CogRadNet: Ubiquitous heterogeneous wireless networks
Mobile radio systems have shown rapid growth and hence increase the awareness for more efficient use of spectrum. With the advancements of technology, the development of radio systems that is dynamic and efficient in
terms of spectrum usage can be realized. Cognitive radio system is one of the advancement that enhanced the adaptive capabilities of the systems that make the usage of spectrum more efficient, versatile and flexible. It also able to adapt their operations based on its internal and external factors by sensing its environment. The cognitive radio systems may be a solution for the spectrum scarcity faced by developer to tackle the issue of signal propagation and bigger coverage for broadband internet access. This paper will addressed the cognitive radio technology for ubiquitous broadband wireless internet access
Feasibility study of using IEEE 802.22 Wireless Regional Area Network (WRAN) in Malaysia
This paper introduces the implementation of IEEE 802.22 Wireless Regional Area Network (WRAN) for broadband Internet access in rural areas.It highlights the advantage of implementing such technology and feasibility to co-exist with Digital Video Broadcasting-Terrestrial (DVB-T) in Malaysia. It adopts a model to determine the maximum number of WRAN base stations (BSs) by analyzing its co-channel interference between the BSs. The analysis shown that maximum WRAN BSs that could co-exist is 8 to 19 BSs outside the protection contour of the DVB-T BS. Coverage areas of 30-100 km will also feasible to co-exist. By implementing the IEEE 802.22 WRAN, the digital divide can be narrowed and broadband penetration would be increased
Fuzzy logic-based intelligent scheme for enhancing QoS of vertical handover decision in vehicular ad-hoc networks
The design of next generation networks in various technologies under the “Anywhere, Anytime” paradigm offers seamless connectivity across different coverage. A conventional algorithm such as RSSThreshold algorithm, that only uses the received strength signal (RSS) as a metric, will decrease handover performance regarding handover latency, delay, packet loss, and handover failure probability. Moreover, the RSS-based algorithm is
only suitable for horizontal handover decision to examine the quality of service (QoS) compared to the vertical handover decision in advanced technologies. In the next generation network, vertical handover can be started based on the user’s convenience or choice rather than connectivity reasons. This study proposes a vertical handover decision algorithm that uses a
Fuzzy Logic (FL) algorithm, to increase QoS performance in heterogeneous vehicular ad-hoc
networks (VANET). The study uses network simulator 2.29 (NS 2.29) along with the mobility traffic network and generator to implement simulation scenarios and topologies. This helps the
simulation to achieve a realistic VANET mobility scenario. The required analysis on the performance of QoS in the vertical handover can thus be conducted. The proposed Fuzzy Logic algorithm shows improvement over the conventional algorithm (RSSThreshold) in the average percentage of handover QoS whereby it achieves 20%, 21% and 13% improvement on handover latency, delay, and packet loss respectively. This is achieved through triggering a process in layer two and three that enhances the handover performance
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