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- Title
- Local construction of connected dominating sets in wireless ad hoc networks.
- Creator
- Dai, Fei., Florida Atlantic University, Wu, Jie, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
Wireless ad hoc networks are infrastructure-less multi-hop networks consisting of mobile (such as in mobile ad hoc networks) or stationary (such as in wireless sensor networks) wireless devices. These networks involve several challenges, including limited bandwidth and energy resources, frequent topology changes, and a lack of central control. Local acting, self-organizing, and self-healing algorithms (also called localized algorithms) are essential to the design of wireless ad hoc networks....
Show moreWireless ad hoc networks are infrastructure-less multi-hop networks consisting of mobile (such as in mobile ad hoc networks) or stationary (such as in wireless sensor networks) wireless devices. These networks involve several challenges, including limited bandwidth and energy resources, frequent topology changes, and a lack of central control. Local acting, self-organizing, and self-healing algorithms (also called localized algorithms) are essential to the design of wireless ad hoc networks. A connected dominating set (CDS) is frequently used in wireless ad hoc networks as a virtual backbone to support efficient routing, service discovery, and area monitoring. In addition, efficient broadcasting (i.e., finding a small set of forward nodes to ensure full delivery) can be viewed as forming a CDS on-the-fly. The periodically maintained virtual backbone is called a static CDS, and the temporarily formed forward node set is called a dynamic CDS. For efficiency and robustness, the ideal CDS construction algorithm is lightweight, has fast convergence, and minimizes the CDS size. This dissertation focuses on providing a generic framework to unify localized CDS construction schemes, including both static and dynamic CDS constructions, for wireless ad hoc networks. The goal is to provide insights on how to form a small CDS (forward node set) in dynamic networks with affordable overhead and high robustness. A classification of CDS construction algorithms for wireless ad hoc networks has been provided at the beginning. An efficient scheme, called Rule K, has been proposed for static CDS construction. Rule K achieves a probabilistic constant upper bound on the expected CDS size, which is currently the best known performance guarantee for localized CDS algorithms. Rule K has been extended to a unified framework, called the coverage condition, which contains most existing localized virtual backbone construction and efficient broadcast algorithms as its special cases. The coverage condition has been further extended to construct a k-connected k-dominating set for higher robustness, and integrated in an iterative process that further reduces the CDS size while maintaining the same level of robustness.
Show less - Date Issued
- 2005
- PURL
- http://purl.flvc.org/fcla/dt/12144
- Subject Headings
- Wireless communication systems, Electronic digital computers--Power supply, Mobile computing, Sensor networks
- Format
- Document (PDF)
- Title
- Integrating Multi-user Scheduling with Retransmission Diversity over Wireless Links.
- Creator
- Li, Irena, Zhuang, Hanqi, Wang, Xin, Florida Atlantic University, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
Research presented in this thesis develops a mainly theoretical basis and computer models for enhancing the throughput of multi-user wireless communication networks. The cross-layer combination of an adaptive modulation and coding (AMC) scheme at the physical layer and the use of automatic repeat request (ARQ) retransmi ssions at the data link layer is integrated into a scheduling framework for multi-user networks. Scheduling algorithms incorporating retransmission diversity are derived for...
Show moreResearch presented in this thesis develops a mainly theoretical basis and computer models for enhancing the throughput of multi-user wireless communication networks. The cross-layer combination of an adaptive modulation and coding (AMC) scheme at the physical layer and the use of automatic repeat request (ARQ) retransmi ssions at the data link layer is integrated into a scheduling framework for multi-user networks. Scheduling algorithms incorporating retransmission diversity are derived for three cases of typical network traffic: best-effort, non-realtime, and realtime. For each case, numeric computer si mulations of wireless communications over Nakagami-m block fading channels are developed to examine the effectiveness of the formulated schemes.
Show less - Date Issued
- 2008
- PURL
- http://purl.flvc.org/fau/fd/FA00012533
- Subject Headings
- Wireless communication networks, Code division multiple access, Modulation (Electronics), Signal processing (Digital techniques)
- Format
- Document (PDF)
- Title
- Estimation of information: Theoretics-based delay bounds of MPEG traffic over ATM networks.
- Creator
- Jagannathan, Shuba., Florida Atlantic University, Hsu, Sam, Neelakanta, Perambur S.
- Abstract/Description
-
This thesis addresses a method to deduce the statistical bounds associated with the cell-transfer delay variations (CDVs) encountered by the cells of MPEG traffic, transmitted in the Asynchronous Transfer Mode (ATM) networks. This study focuses on: (1) Estimating CDV arising from multiplexing/switching for both constant bit rate (CBR) and variable bit rate (VBR) traffics via priority allocation based simulations. (2) Developing an information-theoretics based technique to get an insight of...
Show moreThis thesis addresses a method to deduce the statistical bounds associated with the cell-transfer delay variations (CDVs) encountered by the cells of MPEG traffic, transmitted in the Asynchronous Transfer Mode (ATM) networks. This study focuses on: (1) Estimating CDV arising from multiplexing/switching for both constant bit rate (CBR) and variable bit rate (VBR) traffics via priority allocation based simulations. (2) Developing an information-theoretics based technique to get an insight of the combined BER-induced and multiplexing/switching-induced CDVs in ATM networks. Algorithms pertinent to CDV statistics are derived and the lower and upper bounds of the statistics are obtained via simulations in respect of CBR and VBR traffics. Ascertaining these bounds is useful in the cell admission control (CAC) strategies adopted in ATM transmissions. Inferential remarks indicating the effects of traffic parameters (such as bandwidth, burstiness etc.) on the values of the statistical bounds are presented, and scope for further work are presented.
Show less - Date Issued
- 1998
- PURL
- http://purl.flvc.org/fcla/dt/15577
- Subject Headings
- Asynchronous transfer mode, Broadband communication systems, Integrated services digital networks, Information theory
- Format
- Document (PDF)
- Title
- A unified end-to-end priority strategy for traffic control in an ATM-based broadband ISDN.
- Creator
- Bemmel, Vincent Egbert., Florida Atlantic University, Ilyas, Mohammad, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
In order to guarantee a committed Quality of Service (QoS) to the users of a Broadband Integrated Services Digital Network (B-ISDN), preventive congestion control becomes critical, and is implemented through Call Acceptance Control (CAC) and Usage Parameter Control (UPC) functions. Currently, Asynchronous Transfer Mode (ATM) cells are equipped with a 1-bit Cell Loss Priority (CLP) field, which can be used for service-oriented and/or UPC marking. This creates a conflict, since these two...
Show moreIn order to guarantee a committed Quality of Service (QoS) to the users of a Broadband Integrated Services Digital Network (B-ISDN), preventive congestion control becomes critical, and is implemented through Call Acceptance Control (CAC) and Usage Parameter Control (UPC) functions. Currently, Asynchronous Transfer Mode (ATM) cells are equipped with a 1-bit Cell Loss Priority (CLP) field, which can be used for service-oriented and/or UPC marking. This creates a conflict, since these two marking approaches may have contradicting objectives, and are designed to operate independently. Moreover, by admitting excessive cells as marked traffic, this group is allowed to grow uncontrollably, thereby jeopardizing the QoS committed to other marked cells. This dissertation presents a solution to these problems by proposing a new 4-class priority strategy that unifies the two marking approaches, and is based on a 2-bit CLP field. The impacts of the new priority scheme are triple-fold: (I) For the UPC, a new scheme, the Forgiving Leaky Bucket (FLB), not only carries priorities through subnetwork boundaries, but also has the power of unmarking, i.e. forgiving, previously marked cells, depending on the bandwidth availability in the entering subnetwork. Forgiving will correct access-point bias, a phenomenon observed in internetworked ATM subnetworks of different congestion conditions. (II) At ATM switching nodes, a new space priority scheme is based on a hybrid of the Nested Threshold, and Push-Out cell discarding methods. This scheme is designed for the 4-class priority strategy, and improves the quality of the low priority traffic. (III) In interfacing High Speed Local Area Networks and Metropolitan Area Networks, idle bandwidth due to STM multiplexing is utilized to carry marked excessive cells of connection-oriented variable bit rate traffic, in addition to the service-oriented marking performed at transmitting stations. The resulting stream is then carried through internetworking points, subject to FLB adjustments. As a result, the STM and ATM subnetworks will support a uniform end-to-end priority strategy, essential for a B-ISDN. The proposed impacts are analyzed and compared with conventional implementations, and future directions are indicated.
Show less - Date Issued
- 1993
- PURL
- http://purl.flvc.org/fcla/dt/12334
- Subject Headings
- Integrated services digital networks, Broadband communication systems, Computer networks--Management, Packet switching (Data transmission)
- Format
- Document (PDF)
- Title
- Synchronization in digital wireless radio receivers.
- Creator
- Nezami, Mohamed Khalid., Florida Atlantic University, Sudhakar, Raghavan, Helmken, Henry, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
Time Division Multiple Access (TDMA) architecture is an established technology for digital cellular, personal and satellite communications, as it supports variable data rate transmission and simplified receiver design. Due to transmission bandwidth restrictions, increasing user demands and the necessity to operate at lower signal-to-noise ratio (SNR), the TDMA systems employ high order modulation schemes such as M-ary Quadrature Amplitude Modulation (M-QAM) and burst transmission. Use of such...
Show moreTime Division Multiple Access (TDMA) architecture is an established technology for digital cellular, personal and satellite communications, as it supports variable data rate transmission and simplified receiver design. Due to transmission bandwidth restrictions, increasing user demands and the necessity to operate at lower signal-to-noise ratio (SNR), the TDMA systems employ high order modulation schemes such as M-ary Quadrature Amplitude Modulation (M-QAM) and burst transmission. Use of such techniques in low SNR fading channels causes degradations of carrier frequency error, phase rotation error, and symbol timing jitter. To compensate for the severe degradation due to additive white Gaussian noise (AWGN) and channel impairments, precise and robust synchronization algorithms are required. This dissertation deals with the synchronization techniques for TDMA receivers using short burst mode transmission with emphasis on preamble-less feedforward synchronization schemes. The objective is to develop new algorithms for symbol timing, carrier frequency offset acquisition, and carrier phase tracking using preamble-less synchronization techniques. To this end, the currently existing synchronization algorithms are surveyed and analyzed. The performance evaluation of the developed algorithms is conducted through Monte-Carlo simulations and theoretical analyses. The statistical properties of the proposed algorithms in AWGN and fading channels are evaluated in terms of the mean and variance of the estimated synchronization errors and their Cramer-Rao lower bounds. Based on the investigation of currently employed feedforward symbol timing algorithms, two new symbol timing recovery schemes are proposed for 16-QAM land mobile signals operating in fading channels. Both schemes achieve better performance in fading channels compared to their existing counterparts without increasing the complexity of the receiver implementation. Further, based on the analysis of currently employed carrier offset and carrier phase recovery algorithms, two new algorithms are proposed for carrier acquisition and carrier tracking of mobile satellite systems utilizing short TDMA bursts with large frequency offsets. The proposed algorithms overcome some of the conventional problems associated with currently employed carrier recovery schemes in terms of capture range, speed of convergence, and stability.
Show less - Date Issued
- 2001
- PURL
- http://purl.flvc.org/fcla/dt/11947
- Subject Headings
- Radio--Receivers and reception, Digital communications, Time division multiple access
- Format
- Document (PDF)
- Title
- Like, Follow, Share.
- Creator
- Goodarzi, Naghmeh, Afanador Llach, Camila, Florida Atlantic University, Dorothy F. Schmidt College of Arts and Letters, Department of Visual Arts and Art History
- Abstract/Description
-
My intention for this show is to explore the effect of alienation that ironically is being produced by social media. The principal concept is developed around shame, sharing, and notoriety on three different social media platforms, including Facebook, Instagram, and Telegram. This show explores the social media perception of myself in the realms of human interaction, identity, and memory in social media through the critical appropriation of the languages of design and photography. The...
Show moreMy intention for this show is to explore the effect of alienation that ironically is being produced by social media. The principal concept is developed around shame, sharing, and notoriety on three different social media platforms, including Facebook, Instagram, and Telegram. This show explores the social media perception of myself in the realms of human interaction, identity, and memory in social media through the critical appropriation of the languages of design and photography. The installation with four Facebook profile pictures in large scale and framed looks at the way a personal image can convey the impression of widely different personalities. The selections of personal exchanges over Facebook and Instagram show the degree to which social media creates its own visual language and mode of communication, which sometimes becomes separated from reality and intention. The show extends its reach to performance and direct interaction with the viewer through the availability of stickers for comments by the profile pictures and a third area, where viewers can write or draw their own messages through the simple medium of chalk, which can then be rendered in virtual form through posts on a specially created webpage. The viewer should thus be challenged to ask, to what degrees do words and images communicate the essence of our selves and our own will.
Show less - Date Issued
- 2016
- PURL
- http://purl.flvc.org/fau/fd/FA00004731, http://purl.flvc.org/fau/fd/FA00004731
- Subject Headings
- Self-presentation., Online social networks., Social media--Semiotics., Digital communications--Social aspects., Digital media--Social aspects., Internet--Social aspects., Visual communication--Digital techniques., Emoticons., Social conflict in mass media., .
- Format
- Document (PDF)
- Title
- Transmitter-receiver system for time average fourier telescopy.
- Creator
- Pava, Diego F., Rhodes, William T., Florida Atlantic University, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
Time Average Fourier Telescopy (TAFT) has been proposed as a means for obtaining high-resolution, diffraction-limited images over large distances through ground-level horizontal-path atmospheric turbulence. Image data is collected in the spatial-frequency, or Fourier, domain by means of Fourier Telescopy; an inverse two dimensional Fourier transform yields the actual image. TAFT requires active illumination of the distant object by moving interference fringe patterns. Light reflected from the...
Show moreTime Average Fourier Telescopy (TAFT) has been proposed as a means for obtaining high-resolution, diffraction-limited images over large distances through ground-level horizontal-path atmospheric turbulence. Image data is collected in the spatial-frequency, or Fourier, domain by means of Fourier Telescopy; an inverse two dimensional Fourier transform yields the actual image. TAFT requires active illumination of the distant object by moving interference fringe patterns. Light reflected from the object is collected by a “light-bucket” detector, and the resulting electrical signal is digitized and subjected to a series of signal processing operations, including an all-critical averaging of the amplitude and phase of a number of narrow-band signals.
Show less - Date Issued
- 2014
- PURL
- http://purl.flvc.org/fau/fd/FA00004314
- Subject Headings
- Digital communications, Fourier analysis, Fourier integral operators, Interconnects (Integrated circuit technology), Radio -- Transmitter receivers -- Design and construction, Spread spectrum communications, Wireless sensor networks
- Format
- Document (PDF)
- Title
- Broadband-ISDN signaling: Protocol description and enhancements for future services.
- Creator
- Vasi, Idris Taher., Florida Atlantic University, Lobo, Andrea, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
Broadband-ISDN Network Architecture and Signaling concepts are described with particular emphasis on Asynchronous Transfer Mode (ATM) technology. A consolidated view of various aspects of B-ISDN/ATM Access and Network Signaling functions, architecture and protocols is presented. Additionally, a suggested evolutionary growth path for the B-ISDN signaling protocols is summarized. This is followed by a high-level comparison of two protocols under consideration for network signaling. The result...
Show moreBroadband-ISDN Network Architecture and Signaling concepts are described with particular emphasis on Asynchronous Transfer Mode (ATM) technology. A consolidated view of various aspects of B-ISDN/ATM Access and Network Signaling functions, architecture and protocols is presented. Additionally, a suggested evolutionary growth path for the B-ISDN signaling protocols is summarized. This is followed by a high-level comparison of two protocols under consideration for network signaling. The result of this evaluation indicates that the requirements of network signaling are best met by a protocol stack based on SS7 concepts. Finally, a set of future B-ISDN and Multimedia services is presented in context of the requirements they would impose on the signaling protocols. Enhancements to the access signaling protocol are proposed for the support of multiconnection and/or multiparty calls. These extensions/enhancements consist of a set of simplified messages, information elements and procedures based on message flows. Evolution and backward compatibility to existing protocols are taken into account while developing the extensions.
Show less - Date Issued
- 1994
- PURL
- http://purl.flvc.org/fcla/dt/15016
- Subject Headings
- Asynchronous transfer mode, Computer network architectures, Broadband communication systems, Data transmission systems, Computer network protocols, Integrated services digital networks
- Format
- Document (PDF)
- Title
- A feedback-based multimedia synchronization technique for distributed systems.
- Creator
- Ehley, Lynnae Anne., Florida Atlantic University, Ilyas, Mohammad, Furht, Borko, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
Multimedia applications incorporate the use of more than one type of media, i.e., voice, video, data, text and image. With the advances in high-speed communication, the ability to transmit multimedia is becoming widely available. One of the means of transport for multimedia in distributed networks is Broadband Integrated Services Digital Network (B-ISDN). B-ISDN supports the transport of large volumes of data with a low error rate. It also handles the burstiness of multimedia traffic by...
Show moreMultimedia applications incorporate the use of more than one type of media, i.e., voice, video, data, text and image. With the advances in high-speed communication, the ability to transmit multimedia is becoming widely available. One of the means of transport for multimedia in distributed networks is Broadband Integrated Services Digital Network (B-ISDN). B-ISDN supports the transport of large volumes of data with a low error rate. It also handles the burstiness of multimedia traffic by providing dynamic bandwidth allocation. When multimedia is requested for transport in a distributed network, different Quality of Service (QOS) may be required for each type of media. For example, video can withstand more errors than voice. In order to provide, the most efficient form of transfer, different QOS media are sent using different channels. By using different channels for transport, jitter can impose skews on the temporal relations between the media. Jitter is caused by errors and buffering delays. Since B-ISDN uses Asynchronous Transfer Mode (ATM) as its transfer mode, the jitter that is incurred can be assumed to be bounded if traffic management principles such as admission control and resource reservation are employed. Another network that can assume bounded buffering is the 16 Mbps token-ring LAN when the LAN Server (LS) Ultimedia(TM) software is applied over the OS/2 LAN Server(TM) (using OS/2(TM)). LS Ultimedia(TM) reserves critical resources such as disk, server processor, and network resources for multimedia use. In addition, it also enforces admission control(1). Since jitter is bounded on the networks chosen, buffers can be used to realign the temporal relations in the media. This dissertation presents a solution to this problem by proposing a Feedback-based Multimedia Synchronization Technique (FMST) to correct and compensate for the jitter that is incurred when media are received over high speed communication channels and played back in real time. FMST has been implemented at the session layer for the playback of the streams. A personal computer was used to perform their synchronized playback from a 16 Mbps token-ring and from a simulated B-ISDN network.
Show less - Date Issued
- 1994
- PURL
- http://purl.flvc.org/fcla/dt/12382
- Subject Headings
- Multimedia systems, Broadband communication systems, Data transmission systems, Integrated services digital networks, Electronic data processing--Distributed processing
- Format
- Document (PDF)
- Title
- Combined spatial diversity and time equalization for broadband multiple channel underwater acoustic communications.
- Creator
- Skoro Kaskarovska, Violeta, Beaujean, Pierre-Philippe, Florida Atlantic University, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
High data rate acoustic communications become feasible with the use of communication systems that operate at high frequency. The high frequency acoustic transmission in shallow water endures severe distortion as a result of the extensive intersymbol interference and Doppler shift, caused by the time variable multipath nature of the channel. In this research a Single Input Multiple Output (SIMO) acoustic communication system is developed to improve the reliability of the high data rate...
Show moreHigh data rate acoustic communications become feasible with the use of communication systems that operate at high frequency. The high frequency acoustic transmission in shallow water endures severe distortion as a result of the extensive intersymbol interference and Doppler shift, caused by the time variable multipath nature of the channel. In this research a Single Input Multiple Output (SIMO) acoustic communication system is developed to improve the reliability of the high data rate communications at short range in the shallow water acoustic channel. The proposed SIMO communication system operates at very high frequency and combines spatial diversity and decision feedback equalizer in a multilevel adaptive configuration. The first configuration performs selective combining on the equalized signals from multiple receivers and generates quality feedback parameter for the next level of combining.
Show less - Date Issued
- 2015
- PURL
- http://purl.flvc.org/fau/fd/FA00004411, http://purl.flvc.org/fau/fd/FA00004411
- Subject Headings
- Adaptive signal processing, MIMO systems, Mobile geographic information systems, Signal processing -- Digital techniques, Underwater acoustic telemetry, Underwater acoustics -- Evaluation, Wireless communication systems
- Format
- Document (PDF)
- Title
- Face Processing Using Mobile Devices.
- Creator
- James, Jhanon, Marques, Oge, Florida Atlantic University, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
Image Processing and Computer Vision solutions have become commodities for software developers, thanks to the growing availability of Application Program- ming Interfaces (APIs) that encapsulate rich functionality, powered by advanced al- gorithms. To understand and create an e cient method to process faces in images by computers, one must understand how the human visual system processes them. Face processing by computers has been an active research area for about 50 years now. Face detection...
Show moreImage Processing and Computer Vision solutions have become commodities for software developers, thanks to the growing availability of Application Program- ming Interfaces (APIs) that encapsulate rich functionality, powered by advanced al- gorithms. To understand and create an e cient method to process faces in images by computers, one must understand how the human visual system processes them. Face processing by computers has been an active research area for about 50 years now. Face detection has become a commodity and is now incorporated into simple devices such as digital cameras and smartphones. An iOS app was implemented in Objective-C using Microsoft Cognitive Ser- vices APIs, as a tool for human vision and face processing research. Experimental work on image compression, upside-down orientation, the Thatcher e ect, negative inversion, high frequency, facial artifacts, caricatures and image degradation were completed on the Radboud and 10k US Adult Faces Databases along with other images.
Show less - Date Issued
- 2016
- PURL
- http://purl.flvc.org/fau/fd/FA00004770, http://purl.flvc.org/fau/fd/FA00004770
- Subject Headings
- Image processing--Digital techniques., Mobile communication systems., Mobile computing., Artificial intelligence., Human face recognition (Computer science), Computer vision., Optical pattern recognition.
- Format
- Document (PDF)
- Title
- Implementing security in an IP Multimedia Subsystem (IMS) next generation network - a case study.
- Creator
- Ortiz-Villajos, Jose M., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
The IP Multimedia Subsystem (IMS) has gone from just a step in the evolution of the GSM cellular architecture control core, to being the de-facto framework for Next Generation Network (NGN) implementations and deployments by operators world-wide, not only cellular mobile communications operators, but also fixed line, cable television, and alternative operators. With this transition from standards documents to the real world, engineers in these new multimedia communications companies need to...
Show moreThe IP Multimedia Subsystem (IMS) has gone from just a step in the evolution of the GSM cellular architecture control core, to being the de-facto framework for Next Generation Network (NGN) implementations and deployments by operators world-wide, not only cellular mobile communications operators, but also fixed line, cable television, and alternative operators. With this transition from standards documents to the real world, engineers in these new multimedia communications companies need to face the task of making these new networks secure against threats and real attacks that were not a part of the previous generation of networks. We present the IMS and other competing frameworks, we analyze the security issues, we present the topic of Security Patterns, we introduce several new patterns, including the basis for a Generic Network pattern, and we apply these concepts to designing a security architecture for a fictitious 3G operator using IMS for the control core.
Show less - Date Issued
- 2009
- PURL
- http://purl.flvc.org/FAU/186763
- Subject Headings
- Electronic digital computers, Programming, Computer networks, Security measures, TCP/IP (Computer network protocol), Security measures, Internet Protocol Multimedia Subsystem (IMS), Security measures, Multimedia communications, Security measures
- Format
- Document (PDF)
- 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.
Show less - 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)
- Title
- Studies on Stochastic Multi-user Scheduling in Wireless Communication.
- Creator
- Wang, Di, Morgera, Salvatore D., Wang, Xin, Florida Atlantic University, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
We developed a cross layer design which combines retransmission diversity and multi-user diversity for wireless communication. To this end, a joint design of adaptive modulation and coding with retransmission-based automatic repeat request protocol is outlined. This design is applied to devise multi-user scheduling schemes, which can optimally capture the available multi-user and retransmission diversities. In addition, the proposed on-line scheduling algorithms can operate even when the...
Show moreWe developed a cross layer design which combines retransmission diversity and multi-user diversity for wireless communication. To this end, a joint design of adaptive modulation and coding with retransmission-based automatic repeat request protocol is outlined. This design is applied to devise multi-user scheduling schemes, which can optimally capture the available multi-user and retransmission diversities. In addition, the proposed on-line scheduling algorithms can operate even when the underl ying fading channel distribution is unknown, while asymptotically converging to the offline benchmark with guarantees on prescribed fairness and rate requirements. Numerical results are provided to verify the merits of our novel schemes for multi-user transmissions over Nakagami block fading channels.
Show less - Date Issued
- 2008
- PURL
- http://purl.flvc.org/fau/fd/FA00012568
- Subject Headings
- Stochastic processes--Data processing, Wireless communication systems, Computer network protocols, Code division multiple access, Modulation (Electronics), Signal processing--Digital techniques
- Format
- Document (PDF)