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Impact of interference on connectivity and outage performances in wireless communication networks
Title
Impact of interference on connectivity and outage performances in wireless communication networks: interference-based channel models.
Creator
Mukasa, Constantine, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
Abstract/Description
In recent years, a plethora of wireless applications such as Bluetooth and Ultra-wide band (UWB) radio have emerged. This drastic increase has overly congested the spectrum. So, new networks such as cognitive radios that can solve the spectrum congestion have emerged. But in such networks, interference is introduced at the physical layer. We study and develop an interference model capable of capturing the intrinsic characteristics of the coexistence of such wireless applications. We...
Show moreIn recent years, a plethora of wireless applications such as Bluetooth and Ultra-wide band (UWB) radio have emerged. This drastic increase has overly congested the spectrum. So, new networks such as cognitive radios that can solve the spectrum congestion have emerged. But in such networks, interference is introduced at the physical layer. We study and develop an interference model capable of capturing the intrinsic characteristics of the coexistence of such wireless applications. We investigate the effect of interference using device isolation probability or outage probability in presence Rayleigh and Nakagami-m fading at the physical layer and the impact of lognormal shadowing. We assume that the devices are either deterministically placed or randomly distributed according to a Poisson point process. We derive explicit expressions for the isolation probability and outage probability that give insight into how these channel impairments affect communication in these applications. We use computer simulations to validate our analytical results.
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Date Issued
2013
PURL
http://purl.flvc.org/fcla/dt/3362551
Subject Headings
Wireless communication systems, Technological innovations, Wireless communication systems, Mathematical models, Orthogonal frequency division multiplexing
Format
Document (PDF)
Performance analysis of linear diversity schemes in generalized gamma fading channels
Title
Performance analysis of linear diversity schemes in generalized gamma fading channels.
Creator
Piboongungon, Terawat., Florida Atlantic University, Aalo, Valentine A., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
Abstract/Description
The main focus of this dissertation is to analyze the performance of linear diversity schemes operating in generalized gamma fading channels. The generalized gamma fading model is a versatile fading envelope that generalizes many of commonly used statistical models that describe signal fluctuations due to multipath, shadowing, or a mixture of such processes. The traditional linear diversity combining techniques such as maximal ratio combining (MRC), equal gain combining (EGC), and selection...
Show moreThe main focus of this dissertation is to analyze the performance of linear diversity schemes operating in generalized gamma fading channels. The generalized gamma fading model is a versatile fading envelope that generalizes many of commonly used statistical models that describe signal fluctuations due to multipath, shadowing, or a mixture of such processes. The traditional linear diversity combining techniques such as maximal ratio combining (MRC), equal gain combining (EGC), and selection combining (SC) are addressed with reference to generalized gamma fading environments. For the special case of Nakagami fading, new expressions for outage probability and error-rate performance of linear diversity schemes with arbitrary fading parameters are derived in terms of the Lauricella function. Effects of correlated fading are also studied. Their fruitful application to third generation (3G) wideband code division multiple access (WCDMA) systems, particularly for multiple-input multiple-output (MIMO) and 2D-RAKE receivers are demonstrated. The results exhibit a finite integral representation that can be used for fast and accurate numerical computation. A detail study is also done on multivariate generalized gamma fading environments. Relevant statistical characterization of the sum of independent generalized gamma random variables is derived and expressed in terms of the multivariable Fox's H-function. Since numerical evaluation for the multivariate Fox's H-function is difficult, simpler numerical computations are developed using moment generating function and characteristic function approaches. Since some wireless applications may not have enough space among diversity branches, the statistical characterizations of multivariate correlated generalized gamma fading are relevant in such cases. An investigation on the outage performance for multi-branch selection combining is performed for the correlated multivariate generalized gamma channel. Finally, the dissertation summarizes the main results and explores some directions for further studies.
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Date Issued
2005
PURL
http://purl.flvc.org/fcla/dt/12135
Subject Headings
Numerical integration, Wireless communication systems--Mathematical models, Frequency spectra--Mathematical models
Format
Document (PDF)
Reliable Vehicle-to-Vehicle Weighted Localization in Vehicular Networks
Title
Reliable Vehicle-to-Vehicle Weighted Localization in Vehicular Networks.
Creator
Altoaimy, Lina, Mahgoub, Imad, Florida Atlantic University, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
Abstract/Description
Vehicular Ad Hoc Network (VANET) supports wireless communication among vehicles using vehicle-to-vehicle (V2V) communication and between vehicles and infrastructure using vehicle-to-infrastructure (V2I) communication. This communication can be utilized to allow the distribution of safety and non-safety messages in the network. VANET supports a wide range of applications which rely on the messages exchanged within the network. Such applications will enhance the drivers' consciousness and...
Show moreVehicular Ad Hoc Network (VANET) supports wireless communication among vehicles using vehicle-to-vehicle (V2V) communication and between vehicles and infrastructure using vehicle-to-infrastructure (V2I) communication. This communication can be utilized to allow the distribution of safety and non-safety messages in the network. VANET supports a wide range of applications which rely on the messages exchanged within the network. Such applications will enhance the drivers' consciousness and improve their driving experience. However, the efficiency of these applications depends on the availability of vehicles real-time location information. A number of methods have been proposed to fulfill this requirement. However, designing a V2V-based localization method is challenged by the high mobility and dynamic topology of VANET and the interference noise due to objects and buildings. Currently, vehicle localization is based on GPS technology, which is not always reliable. Therefore, utilizing V2V communication in VANET can enhance the GPS positioning. With V2V-based localization, vehicles can determine their locations by exchanging mobility data among neighboring vehicles. In this research work, we address the above challenges and design a realistic V2V-based localization method that extends the centroid localization (CL) by assigning a weight value to each neighboring vehicle. This weight value is obtained using a weighting function that utilizes the following factors: 1) link quality distance between the neighboring vehicles 2) heading information and 3) map information. We also use fuzzy logic to model neighboring vehicles' weight values. Due to the sensitivity and importance of the exchanged information, it is very critical to ensure its integrity and reliability. Therefore, in this work, we present the design and the integration of a mobility data verification component into the proposed localization method, so that only verified data from trusted neighboring vehicles are considered. We also use subjective logic to design a trust management system to evaluate the trustworthiness of neighboring vehicles based on the formulated subjective opinions. Extensive experimental work is conducted using simulation programs to evaluate the performance of the proposed methods. The results show improvement on the location accuracy for varying vehicle densities and transmission ranges as well as in the presence of malicious/untrusted neighboring vehicles.
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Date Issued
2016
PURL
http://purl.flvc.org/fau/fd/FA00004564, http://purl.flvc.org/fau/fd/FA00004564
Subject Headings
Vehicular ad hoc networks (Computer networks)--Mathematical models., Computer communication systems., Wireless communication systems., Routing (Computer network management), Intelligent transportation systems., Intelligent control systems.
Format
Document (PDF)
Adaptive Routing Protocols for VANET
Title
Adaptive Routing Protocols for VANET.
Creator
Skiles, Joanne, Mahgoub, Imad, Florida Atlantic University, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
Abstract/Description
A Vehicular Ad-hoc Network (VANET) is a wireless ad-hoc network that provides communications among vehicles with on-board units and between vehicles and nearby roadside units. The success of a VANET relies on the ability of a routing protocol to ful ll the throughput and delivery requirements of any applications operating on the network. Currently, most of the proposed VANET routing protocols focus on urban or highway environments. This dissertation addresses the need for an adaptive routing...
Show moreA Vehicular Ad-hoc Network (VANET) is a wireless ad-hoc network that provides communications among vehicles with on-board units and between vehicles and nearby roadside units. The success of a VANET relies on the ability of a routing protocol to ful ll the throughput and delivery requirements of any applications operating on the network. Currently, most of the proposed VANET routing protocols focus on urban or highway environments. This dissertation addresses the need for an adaptive routing protocol in VANETs which is able to tolerate low and high-density network tra c with little throughput and delay variation. This dissertation proposes three Geographic Ad-hoc On-Demand Distance Vector (GEOADV) protocols. These three GEOADV routing protocols are designed to address the lack of exibility and adaptability in current VANET routing protocols. The rst protocol, GEOADV, is a hybrid geographic routing protocol. The second protocol, GEOADV-P, enhances GEOADV by introducing predictive features. The third protocol, GEOADV-PF improves optimal route selection by utilizing fuzzy logic in addition to GEOADV-P's predictive capabilities. To prove that GEOADV and GEOADV-P are adaptive their performance is demonstrated by both urban and highway simulations. When compared to existing routing protocols, GEOADV and GEOADV-P lead to less average delay and a higher average delivery ratio in various scenarios. These advantages allow GEOADV- P to outperform other routing protocols in low-density networks and prove itself to be an adaptive routing protocol in a VANET environment. GEOADV-PF is introduced to improve GEOADV and GEOADV-P performance in sparser networks. The introduction of fuzzy systems can help with the intrinsic demands for exibility and adaptability necessary for VANETs. An investigation into the impact adaptive beaconing has on the GEOADV protocol is conducted. GEOADV enhanced with an adaptive beacon method is compared against GEOADV with three xed beacon rates. Our simulation results show that the adaptive beaconing scheme is able to reduce routing overhead, increase the average delivery ratio, and decrease the average delay.
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Date Issued
2017
PURL
http://purl.flvc.org/fau/fd/FA00004926, http://purl.flvc.org/fau/fd/FA00004926
Subject Headings
Vehicular ad hoc networks (Computer networks)--Design and construction., Routing protocols (Computer network protocols), Wireless sensor networks., Computer algorithms., Mobile computing., Mobile communication systems--Technological innovations., Wireless communication systems--Technological innovations., Intelligent transportation systems--Mathematical models.
Format
Document (PDF)
Stochastic optimization of energy for multi-user wireless networks over fading channels
Title
Stochastic optimization of energy for multi-user wireless networks over fading channels.
Creator
Wang, Di, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
Abstract/Description
Wireless devices in wireless networks are powered typically by small batteries that are not replaceable nor recharged in a convenient way. To prolong the operating lifetime of networks, energy efficiency is indicated as a critical issue and energy-efficient resource allocation designs have been extensively developed. We investigated energy-efficient schemes that prolong network operating lifetime in wireless sensor networks and in wireless relay networks. In Chapter 2, the energy-efficient...
Show moreWireless devices in wireless networks are powered typically by small batteries that are not replaceable nor recharged in a convenient way. To prolong the operating lifetime of networks, energy efficiency is indicated as a critical issue and energy-efficient resource allocation designs have been extensively developed. We investigated energy-efficient schemes that prolong network operating lifetime in wireless sensor networks and in wireless relay networks. In Chapter 2, the energy-efficient resource allocation that minimizes a general cost function of average user powers for small- or medium-scale wireless sensor networks, where the simple time-division multiple-access (TDMA) is adopted as the multiple access scheme. A class of Ç-fair cost-functions is derived to balance the tradeoff between efficiency and fairness in energy-efficient designs. Based on such cost functions, optimal channel-adaptive resource allocation schemes are developed for both single-hop and multi-hop TDMA sensor networks. In Chapter 3, optimal power control methods to balance the tradeoff between energy efficiency and fairness for wireless cooperative networks are developed. It is important to maximize power efficiency by minimizing power consumption for a given quality of service, such as the data rate; it is also equally important to evenly or fairly distribute power consumption to all nodes to maximize the network life. The optimal power control policy proposed is derived in a quasi-closed form by solving a convex optimization problem with a properly chosen cost-function. To further optimize a wireless relay network performance, an orthogonal frequency division multiplexing (OFDM) based multi-user wireless relay network is considered in Chapter 4., In the OFDM approach, each subcarrier is dynamically assigned to a source- destination link, and several relays assist communication between pairs of source-destination over their assigned subcarriers. Using a class of Ç-fair cost-functions to balance the tradeoff between energy efficiency and fairness, jointly with optimal subcarrier and power allocation schemes at the relays. Relevant algorithms are derived in quasi-closed form. Lastly, the proposed energy-efficient schemes are summarized and future work is discussed in Chapter 5.
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Date Issued
2011
PURL
http://purl.flvc.org/FAU/3322519
Subject Headings
Stochastic processes, Data processing, Wireless communication systems, Mathematical models, Computer network protocols, Signal processing, Digital techniques, Code division multiple access, Waveless division multiplexing, Orthogonalization methods
Format
Document (PDF)
Implementations Of The DTM, DADCQ And SLAB VANET Broadcast Protocols For The Ns-3 Simulator
Title
Implementations Of The DTM, DADCQ And SLAB VANET Broadcast Protocols For The Ns-3 Simulator.
Creator
Alwakeel, Ahmed M., Mahgoub, Imad, Florida Atlantic University, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
Abstract/Description
This work presents the implementations of three adaptive broadcast protocols for vehicular ad hoc networks (VANET) using the Network Simulator 3 (Ns-3). Performing real life tests for VANET protocols is very costly and risky, so simulation becomes a viable alternative technique. Ns-3 is one of the most advanced open source network simulators. Yet Ns-3 lacks implementations of broadcast protocols for VANET. We first implement the Distance to Mean (DTM) protocol, which uses the distance to mean...
Show moreThis work presents the implementations of three adaptive broadcast protocols for vehicular ad hoc networks (VANET) using the Network Simulator 3 (Ns-3). Performing real life tests for VANET protocols is very costly and risky, so simulation becomes a viable alternative technique. Ns-3 is one of the most advanced open source network simulators. Yet Ns-3 lacks implementations of broadcast protocols for VANET. We first implement the Distance to Mean (DTM) protocol, which uses the distance to mean to determine if a node should rebroadcast or not. We then implement the Distribution-Adaptive Distance with Channel Quality (DADCQ) protocol, which uses node distribution, channel quality and distance to determine if a node should favor rebroadcasting. The third protocol, Statistical Location-Assisted Broadcast protocol (SLAB), is an improvement of DADCQ which automates the threshold function design using machine learning. Our NS-3 implementations of the three protocols have been validated against their JiST/SWANS implementations.
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Date Issued
2016
PURL
http://purl.flvc.org/fau/fd/FA00004565, http://purl.flvc.org/fau/fd/FA00004565
Subject Headings
Vehicular ad hoc networks (Computer networks)--Technological innovations., Wireless communication systems--Technological innovations., Mobile communication systems--Technological innovations., Mobile computing., Intelligent transportation systems--Mathematical models., Routing protocols (Computer network protocols)
Format
Document (PDF)