WorldCat Identities

Cioffi, John M.

Works: 35 works in 51 publications in 2 languages and 250 library holdings
Roles: Thesis advisor, Author
Publication Timeline
Most widely held works by John M Cioffi
Understanding digital subscriber line technology by Thomas Starr( Book )

13 editions published between 1998 and 1999 in English and held by 176 WorldCat member libraries worldwide

Accompanying CD-ROM includes Adobe Acrobat Reader version 3.01 ; drafts of the XDSL standards, ISDN ; HDSL ; ADSL ; and VDSL
XDSL: eine Einführung : erläutert ISDN, HDSL, ADSL und VDSL by Thomas Starr( Book )

1 edition published in 2000 in German and held by 36 WorldCat member libraries worldwide

Fast transversal filters for communications applications by John M Cioffi( )

4 editions published in 1984 in English and held by 7 WorldCat member libraries worldwide

Discrete multiple tone modulation with coset coding for the spectrally shaped channel by Antonio Ruiz( Book )

2 editions published in 1989 in English and held by 2 WorldCat member libraries worldwide

The design of the energy distribution and coded information allocation over the subchannels is optimized for the finite block length case and for the coset code concatenation, leading to an implementable coding system with optimized performance for the channel with ISI. Asymptotic performance of this system is derived, and examples of asymptotic and finite block length coding gain performance for several channels is evaluated at different values of bits per sample. Using sufficiently long blocks for a particular ISI pattern, it can be shown that the implementable techniques presented here achieve the cut-off rate for any channel with ISI in the presence of additive Gaussian noise
A signal processing approach to overcome data integrity challenges in flash SSD design by Borja Manuel Peleato Inarrea( )

1 edition published in 2012 in English and held by 1 WorldCat member library worldwide

Recently, flash-based Solid State Drives (SSD's) have emerged as a faster and more efficient alternative to hard drives. However, their higher cost is still an obstacle for their widespread use. Manufacturers have significantly reduced the cost by aggressively scaling the technology but this reduction has come at a price in lifetime, speed, and reliability. As the cell size shrinks and more bits are programmed into each one of them, interaction between neighboring cells increases significantly leading to noisier writing and unreliable reading of the flash memory. It is thus a signal processing challenge to write and read back reliably. This thesis proposes methods to overcome this challenge
100-Gbps ethernet over twisted-pairs by Vahbod Pourahmad( )

1 edition published in 2013 in English and held by 1 WorldCat member library worldwide

Ever-increasing network and internet traffic, coupled with continued growth in server capacity, puts higher and higher requirements on interconnections between equipment in data centers. Ethernet over twisted-pair cabling (Base-T) has traditionally been the method of choice for these connections. To be able to meet those higher requirements, a next-generation Base-T technology should ideally be capable of delivering a maximum throughput of up to an order of magnitude higher than today. New techniques are proposed here to increase the data rates achievable over twisted-pairs. A model based on multi-conductor transmission line theory is expanded and used at frequencies up to a few GHz to characterize existing cables, as well as to suggest guidelines for improvements in the future. Lab measurements are then used to both validate this model, as well as to compute data rates achieved by using common-mode (as opposed to the conventional differential-only) signaling in twisted-pairs. It is shown that there is a potential for a significant increase in data rates by exploiting all available modes of energy transfer in this medium. More specifically, under the stated assumptions in Chapter 4, it is shown that only through the use of single-ended signaling is a rate of 100Gbps achievable at 30m with a single cable, and at 100m with four cables
An efficient, RLS, data-driven echo canceller for fast initialization of full-duplex data transmission by John M Cioffi( Book )

1 edition published in 1985 in English and held by 1 WorldCat member library worldwide

Understanding digital subscriber line technology by Thomas Starr( )

1 edition published in 1999 in English and held by 1 WorldCat member library worldwide

Multiple antenna transmitter design under power constraints by T'ae-min Kim( )

1 edition published in 2013 in English and held by 1 WorldCat member library worldwide

Multiple-antenna technique is one of the fundamental building blocks for modern wireless communication systems. The spatial degrees of freedom provided by multiple antennas when used with appropriate transmit coding and receive signal processing, offer several performance advantages including array gain, diversity gain and multiplexing gain. Most theoretical results in multiple-antenna theory assume a sum-power constraint for the transmit antennas. However, practical multiple-antenna transmitters are often subject to per-Power Amplifier (PA) constraint and sometimes also Effective Isotropic Radiated Power (EIRP) constraint. These constraints are motivated by bio-safety, interference reduction and lower cost. However, per-PA power constrained systems suffer from performance loss under imbalances in channel gains at the transmit antennas that often occur in the presence of fading. This thesis studies point-to-point and multi-point-to-point transmission under per-PA power and EIRP constraints, focusing on techniques to increase link performance and to reduce algorithmic complexity. The first part of this thesis studies the use of a Power Combining Network (PCN) to improve link performance under a per-PA power constraint. A PCN switches the outputs of PAs associated with antennas with poor channels to antennas with good channels. The PCN balances the higher coupling gain of the PA power with the loss of array gain or diversity gain. We also study PCN design when an additional EIRP constraint is imposed. We develop fast algorithms for determining the optimal PCN under both a per-PA power constraint alone or with an additional EIRP constraint. We demonstrate the effectiveness of PCN through performance analysis and numerical evaluation. The second part of this thesis is motivated by reducing computational complexity of transmit beamforming algorithms in multi-point-to-point, so called a Coordinated Multi-Point (CoMP), transmission. Algorithmic complexity is high in CoMP since calculating the joint optimal transmit beamformers typically involves an iterative computation of intermediate solutions across the multiple base stations. We present a low-complexity minimum-mean-squared-error beamforming algorithm for CoMP transmission under per-PA power constraint. We decompose the original beamforming problem at each base station into a series of simpler sub-problems. Solution of each sub-problem is derived in a closed-form, and convergence proof and complexity analysis are presented. We demonstrate significant saving in computational complexity without compromising performance which is confirmed by numerical evaluation
Algebraic space-time block codes with manageable complexity of maximum-likelihood detection by Ming-Yang Chen( )

1 edition published in 2011 in English and held by 1 WorldCat member library worldwide

Multiple-input multiple-output (MIMO) wireless systems provide tremendous throughput and reliability gains by utilizing multiple antennas at the transmitters and receivers. As a result, numerous papers have addressed communication and signal-processing topics like space-time code design and signal detection theory. However, today's industry still faces problems with integrating MIMO into products owing to the implementation complexity. Management of complexity is therefore essential to realize the promise of MIMO technology. Previous research on designing space-time block codes was mostly concerned with maximizing transmit diversity and coding gains, and with achieving the optimal diversity-multiplexing trade-off. In contrast, this thesis aims at designing new transmission strategies that can be efficiently decoded while retaining or approaching the optimal performance. The first part of this thesis proposes a new set of rate-1 space-time block codes in systems with 2^n-transmit antennas. These designs achieve the full spatial diversity in quadrature amplitude modulation (QAM). Furthermore, the column vectors of each code matrix can be partitioned into two classes such that any two vectors from different classes are orthogonal. As a result, the maximum-likelihood (ML) detection can be implemented in reduced time complexity. For a system with four transmit antennas, the proposed encoders attain the optimal bit error rate (BER) in QAM without the necessity of extra modulation. These results will be extended to new rate-1 codes employing four transmit antennas for which the ML detection can be determined in linear time. These codes similarly achieve the full diversity in QAM, and moreover in 4M-phase-shift keying (4M-PSK), while the corresponding ML detection can be accomplished by independently decoding each symbol. The reduction in detection complexity simply necessitates an increment of 0.21 dB in the signal-to-noise ratio (SNR) for sustaining the same BER
DSL advances by Thomas Starr( Book )

1 edition published in 2003 in English and held by 1 WorldCat member library worldwide

DSL Advances brings together the state of the art in xDSL technology, architecture, standards, and business cases for every technical professional and manager. The authors of the classic Understanding Digital Subscriber Line Technology review important technical progress made since DSL moved into the mainstream and preview enhancements still on the horizon. Coverage includes ADSL, HDSL2, SHDSL, line unbundling, spectrum management, VoDSL, video-on-demand, DSL in the networked home, CPE auto-configuration, flow-through service provisioning, security, advanced coding techniques, multi-user detection, and much more
Redesign of next-generation broadband-network architectures with limited cooperation, cross-layer scheduling, and dynamic resource allocation by Aakanksha Chowdhery( )

1 edition published in 2013 in English and held by 1 WorldCat member library worldwide

The explosion of internet-enabled devices in home networks, such as smartphones, tablets, laptops, and internet-protocol TV (IPTV), threatens to choke current wire-line and wireless broadband-access speeds and demands an order-of-magnitude improvement. Furthermore, the heterogeneous nature of these devices' traffic requires intelligent management of the access networks' quality-of-service (QoS) guarantees, especially for video traffic. This dissertation investigates the redesign of broadband-access architectures by using limited cooperation to deliver an order-of-magnitude increase in data-rates, and by using cross-layer scheduling and pre-caching protocols to balance the QoS requirements of both data and video traffic. The first part of the dissertation investigates the gains of cooperative communication systems when only a limited number of receivers cooperate. The cooperation benefits in terms of data-rate gains can diminish significantly in such limited cooperation scenarios by using the state-of-the-art algorithms that fail to account for the interference between cooperative and non-cooperative links. Novel dynamic spectrum management (DSM) techniques are proposed to manage such interference and the proposed techniques allow these limited cooperation scenarios to retain most of the cooperation benefits in next-generation cooperative systems while maintaining the performance of legacy non-cooperative systems. Chapter 2 focuses on the theoretical bounds in terms of achievable rate-regions, while Chapter 3 proposes distributed algorithms that can approximate the theoretical performance with low-complexity and practically implementable protocols in wire-line digital-subscriber-line (DSL) systems. The second part of the dissertation investigates the use of cross-layer protocols to balance QoS requirements of heterogeneous data, video, and other multimedia application traffic. Chapter 4 proposes cross-layer protocols for distributed scheduling that exploit the channel or noise cyclo-stationarity to enable higher throughputs for low-priority data traffic while meeting the QoS guarantees of high-priority video traffic, thereby promising to balance internet uplink speeds for both high-priority video traffic and low-priority data traffic in home networks. Chapter 5 proposes novel cross-layer pre-caching protocols to meet the increasing demands of IPTV traffic on wire-line broadband-access networks. IPTV viewers tend to watch at similar periods during the day (e.g. 6-9 PM or Friday nights), creating peak-bandwidth demands on interference-limited networks when there is insufficient physical-layer bandwidth to meet these demands. The proposed protocol estimates the impact of future peak-demand periods on interference-limited networks and pre-allocates bandwidth to deliver the forecasted videos and avoid the peak-demand periods
High-speed digital subscriber lines( Book )

1 edition published in 1991 in English and held by 1 WorldCat member library worldwide

UltraFlow dual-mode access network : physical and system implementation of optical access network by Shuang Yin( )

1 edition published in 2016 in English and held by 1 WorldCat member library worldwide

Optical Flow Switching (OFS) network has been proposed as a complement to the existing Electronic Packet Switching (EPS) based network for its high efficiency in transmitting large files. UltraFlow access network enables OFS in the access network domain, and provides dual-mode services to the end users, i.e., conventional IP and novel Flow. The UltraFlow dual-mode network architecture is a promising solution to the problem of ever-increasing growth of Internet traffic and the newly emerging network applications. The UltraFlow project involves the collaboration of three universities: Stanford University, Massachusetts Institute of Technology (MIT), and University of Texas at Dallas. The MIT group focuses on the design and analysis of OFS in the core and metro network, while the focus of UT Dallas is on designing and analyzing the UltraFlow control plane. At Stanford University, we focus on designing and experimentally demonstrating the UltraFlow dual-mode access network. This dissertation proposes and discusses the concept, architecture, design, implementation and potential applications of the UltraFlow dual-mode access network. The rest of this dissertation is organized as follows. First, this dissertation introduces the concept the UltraFlow dual-mode access network and shows that this architecture is crucial to achieve high throughput transmission considering various Internet traffic patterns. Also presented is the physical layer implementation of UltraFlow dual-mode access network, which coexists with the legacy Passive Optical Networks (PONs). The transport layer design and software defined control plane will also be briefly described. This dissertation next discusses a novel Intra-PON Flow communication architecture, which enables transparent lightpaths among users located in the same access network. Intra-PON channels can support advanced network applications, e.g., video/file server backup, and Coordinated Multipoint (CoMP) transmission in the 5G mobile network era. The proposed architecture adopts a Quasi-PAssive Reconfigurable (QPAR) node, proposed and developed by our group previously, in the UltraFlow access network testbed, which enables dynamic wavelength allocation and improves the UltraFlow dual-mode access network performance. Experimental results then appear on remotely pumped Erbium Doped Fiber Amplifier (EDFA) and distantly powered QPAR node, which can maintain the passive nature of the legacy PONs and achieve high split ratio. This work also investigates and assesses the network performance advantages of Intra-PON Flow transmission via extensive network simulations. Finally, the dissertation reports the line rate evolution paths, beyond state-of-the-art 10 Gbps per wavelength transmission, for the next generation optical access network. This report shows the feasibility of implementing low-cost 25 and 40 Gbps per wavelength transmission in PONs. Advance modulation formats, i.e., Electrical Duobinary (EDB) and 4-level Pulse Amplitude Modulation (PAM-4), optical amplification, and Digital Signal Processing (DSP) are considered as key technologies to support the data rate increase and maintain relatively low system cost with 10 Gbps grade optics. This work includes the experimental results on system power budget, split ratio, and reach for both 25 and 40 Gbps per wavelength transmission with different system designs, and suggests an optimal set of system specifications for both 25 and 40 Gbps transmission
Cooperative wireless communication for cellular and multi-hop networks by HyukJoon Kwon( )

1 edition published in 2010 in English and held by 1 WorldCat member library worldwide

The design of efficient algorithms using cooperation has gained much attention as an emerging technique for the next-generation wireless system. Such a cooperative system allows wireless devices to communicate with each other over relaying. With astute cooperative algorithms, wireless systems are expected to increase sum-rate performance and to support reliable communication. In general, wireless systems can be classified into centralized cellular infrastructures and decentralized ad-hoc multi-hop networks. Cellular networks require high quality channel information to increase sum-rate performance. However, due to finite-rate feedback channels, the base station cannot obtain uncorrupted channel information from mobile stations (MSs), thereby preventing the improvement in the sum-rate performance. On the other hand, multi-hop networks also require high level credit information about neighbor nodes to support reliable communication. Otherwise, traffic is likely to stop at some selfish nodes while being relayed to the destination. The first part of this thesis is motivated with the challenging issue: saving the number of feedback bits while maintaining sum-rate performance. To achieve the objective, this work exploits the cooperation between MSs, known as conferencing, in addition to feedback channels. It has been theoretically shown that cooperating encoders increase the capacity region in multiple-access channels. Similarly, the increase of achievable rate region in broadcast channels with cooperating decoders has been also revealed. In practical systems, the feedback rate is finite as well as cooperation is imperfect. Therefore, it is essential to exploit both cooperation and feedback effectively. Moreover, when multiple MSs are considered, multi-user diversity can be also exploited as yet another independent resource. Using these resources, i.e., feedback, cooperation and user-selection, available in broadcast channels, this thesis introduces the enhancement of the sum-rate performance through rigorous investigation of the relation among the resources. Moreover, this work derives the requirement for the number of feedback bits that achieve the multiplexing gain. Simulation results are presented to evaluate the sum-rate and to verify the derivation. The second part of this thesis focuses on multi-hop networks where each node operates independently without any centralized base stations. This multi-hop network can use cooperation among nodes to increase the total throughput with respect to a single-hop network. However, each node is autonomous and selfish in nature, and thus spontaneous cooperation among nodes is challenged. To accommodate this otherwise selfish nature of multi-hop networks, this thesis proposes a cooperative relay strategy under an energy-limited condition with a game-theoretic perspective. The main focuses are 1) to motivate each node to be cooperative, 2) to decide optimally the amount of cooperation, 3) to analyze equilibrium for the proposed scheme, and thus 4) to maximize the overall throughput. The proposed scheme formulates a Stackelberg game where two nodes sequentially bid their willingness weights to cooperate for their own benefit. Accordingly, all the nodes are encouraged to be cooperative only if a sender is cooperative and alternatively to be non-cooperative only if a sender is non-cooperative. This selective strategy changes the reputations of nodes depending on the amount of their bidding at each game and motivates them to maintain a good reputation so that all their respective packets can be treated well by other relays. Thus, every node forwards other packets with higher probability, thereby achieving a higher overall payoff
The Winning Manager's Playbook by John M Cioffi( Book )

1 edition published in 2013 in English and held by 1 WorldCat member library worldwide

Utility maximization in multiuser, multicarrier, communication systems by Haleema Mehmood( )

1 edition published in 2015 in English and held by 1 WorldCat member library worldwide

This dissertation addresses non-convex utility-maximization problems in multiuser, multicarrier communications systems. Utility maximization is an effective tool for communication system design. Utility functions are used to translate user or design preferences to optimization objectives. Physical-layer resource allocation in a communication system is then based on maximizing the utility of the system. This dissertations formulates a utility-maximization problem with a rate region constraint on the rate vectors. It considers various discrete optimization problems for multiuser, multicarrier communications systems. It presents algorithms that find utility-maximizing rate tuples for concave and non-concave utility functions over rate regions of Gaussian vector multiuser channels. The non-concave functions considered are staircase and sigmoidal utility functions that are widely used utility models for multimedia applications. Using a branch-and-bound method, a sequence of bounds on the optimal objective function value is obtained that converges to the global maximum sum of utilities. At each step, the algorithm solves a concave subproblem for multiuser power allocation using dual decomposition. For multicarrier systems, further decomposition of the Lagrangian across the subcarriers provides a low complexity method for utility maximization. The second part of this dissertation presents the concept of revenue potential as a tool for Internet service providers for revenue-based power allocation. Broadband Internet service providers are for-profit companies. From their perspective, utility of a multiuser channel is the total price they can charge their customers for provision of services. Broadband price functions are generally staircase functions of advertised data rates. The problem of finding the revenue potential of a DSL binder is a utility-maximization problem with a staircase utility function. The problem for the crosstalking DSLs is solved using the branch-and-bound method. A serious crosstalking problem arises in mixed deployments of vectored DSLs, sometimes known as G. Vector, and legacy DSLs. Such deployments require rate control on unvectored lines to realize vectoring gains. Revenue potential is used to determine the optimal-revenue rate-limits for unvectored lines. A strategy that limits the rates offered to the unvectored customers is shown to increase long-term revenue for the ISP. The third part of this dissertation presents a spiderweb plotting technique for multidimensional rate regions. This technique is useful for visualizing subsets of high-dimensional rate regions on a two-dimensional plot. Utility maximization is an alternative to building such rate regions and returns a single useful point instead of multiple data points. Both techniques are useful in different applied contexts. The last part of this dissertation considers a problem of joint user-clustering and bit-allocation for coaxial cable systems. The problem arises in next-generation coaxial cable systems, sometimes known as DOCSIS 3.1, with multicarrier modulation and adaptive bit loading. Users need to be grouped together and assigned bit profiles to maximize spectral efficiency. The problem is a discrete, non-convex, utility-maximization problem. A greedy, coordinate-ascent algorithm is presented to find clustering solutions to the utility-maximization problem. A comparison with optimal solutions found by exhaustive search shows that the algorithm gives close to optimal performance
Managing radio resources in dense wireless areas by Haleh Tabrizi( )

1 edition published in 2013 in English and held by 1 WorldCat member library worldwide

Smartphone proliferation has created the demand for ubiquitous access to wireless data anywhere and at any time. This demand is particularly perceived in crowded venues such as concert halls, conference halls and sports stadiums, where a large number of mobile devices contend for limited spectrum. This dissertation focuses on highly dense wireless areas, where all users must communicate simultaneously with a common destination node, such as a cellular base-station. The research identifies a solution of multiple, small, dynamic user hotspots to better distribute the limited radio resources. This is achieved by taking advantage of reduced pathloss, communicating over locally available spectrum, and reuse of spectrum over spatially separated links. This dissertation presents two different methods of selecting hotspots, routing data and allocating resources in dense wireless areas. The first part of this dissertation focuses on improving network performance by creating a clustered configuration of nodes where the nodes within each cluster can operate over locally available spectrum (white-spaces). A single node within each cluster is designated as the hotspot, and all the other nodes communicate with the destination node through the hotspots. A semi-distributed algorithm, that clusters the nodes and coordinates the hotspots to tether over locally available white-spaces is proposed. In addition to providing simultaneous service to more users than conventional direct communication in cellular networks, simulation results show that the proposed method can increase the average battery life of devices by 30%. The second part of this dissertation aims at improving network performance in dense wireless areas through multiple hops and spatial reuse of spectrum. The proposed method groups nodes based on their location and creates a structured multi-hop configuration in which each group can forward its neighbor's data. Employing the large number of active radio nodes as relays, and exploiting the common direction of communication toward the single destination allows spatially separated groups to reuse limited spectrum resources. Resource allocation and routing among users is formulated as a convex cross-layer optimization problem. Furthermore, exploiting the structure of such problem leads to a semi-distributed optimization algorithm. As such, each node can optimize its resources independently based on local channel information
Rate adaptation in MIMO wireless systems by Tom McGiffen( )

1 edition published in 2013 in English and held by 1 WorldCat member library worldwide

In Multiple Input Multiple Output (MIMO) systems, predicting performance prior to data transmission is needed to appropriately select transmitter parameters (e.g. QAM modulation, code rate). We want to select transmitter parameters aggressive enough to take advantage of the available channel capacity, but not so aggressive that we do not meet desired performance (error) requirements. The prediction must, therefore, be accurate. But, practical considerations must be accommodated as well. The prediction needs to be easy to compute, given limited resources. An algorithm taking too much time to run or excessive circuitry to implement cannot be deployed. Further, the prediction must be tolerant to imprecise data, as deployed hardware often does not know the environment with complete accuracy. This dissertation presents a family of algorithms to accurately predict the average bit error rate (BER) and packet error rate (PER) of a MIMO system. Further, we address these practical considerations of low computational complexity, and imprecise data. Since the algorithms make no a-priori assumptions about the channel, they are applicable to a wide variety of random channels
Optimizing state-information feedback in downlink wireless systems by Rajiv Agarwal( )

1 edition published in 2010 in English and held by 1 WorldCat member library worldwide

Future wireless networks will be driven by various ubiquitous broadband services such as portable telephony, mobile Internet, Voice over IP (VoIP), and IPTV. A cellular network is a radio network distributed over land areas called cells, each served by at least one fixed-location transceiver known as a base-station (BS). A cell is an area of radio coverage in a cellular network that serves multiple mobile users. To accommodate a single cell's large number of users, each running a different application on its mobile terminal, optimization of limited resources is critical. In a cellular network, 'downlink' is the transmission path from the BS to the mobile terminal. In the downlink, feedback of mobile user's condition to the BS is essential for optimal allocation of limited resources, however, it is a system design challenge. Mobile user's condition is comprised of its wireless channel condition, among multiple other such system metrics. Therefore, this thesis explores optimal resource allocation in the downlink, also known as broadcast channel (BC), with limited or partial knowledge of a mobile user's condition, referred to as state information, at the BS. This thesis first explores the case where both the BS and the users are equipped with a single antenna and only channel state information (CSI) constitutes the state-information. In this configuration, multiple forms of partial CSI feedback are studied. The ergodic rate region for a fading broadcast channel, when the transmitter knows only the channel priority (ordering) information of the users at any time instant, is derived. The ergodic rate region is the set of all long-term average data-rates achievable in a fading channel with arbitrarily small probability of error. Next the rate region for a 2-user fading BC, in which instantaneous channel state information at the transmitter (CSIT) is available for only one of the users, is studied. Then, a fading BC with only a quantized version of CSI at the transmitter, is analyzed. Thereby, this thesis explored partial CSIT's three possible definitions. Future wireless systems use multiple antennas both at the transmitter and receiver(s) to achieve a higher data rate. These systems are called multiple input multiple output (MIMO) systems. An important design concern for the MIMO BC is the complexity of the transmission technique to maximize total data-rate for the downlink users. The problem of finding the optimal transmit filter (or beamforming matrix) to maximize total data rate is intractable. This thesis derives a low complexity algorithm for finding a near-optimum transmit filter. Also, an opportunistic feedback (OF) protocol that achieves the highest possible total data rate, also called sum-capacity, in the fading MIMO BC with limited CSI feedback is proposed. A popular transmission technique for downlink is orthogonal frequency division multiple access (OFDMA) and this technique is now a part of almost every next-generation wireless standard. In an OFDMA system, each downlink user is transmitted to on orthogonal sub-carrier(s) or tones. Optimal tone allocation in downlink OFDMA networks is an NP-hard problem that requires extensive feedback for CSI. Two constant complexity limited-feedback algorithms are designed to achieve near-optimal performance. Using opportunistic feedback (OF), the proposed schemes are shown to reduce feedback overhead by requiring only users likely to be allocated resources to feed back. Additionally, the optimal allocation of feedback resources is derived for the case of fixed feedback rate. Specifically, the optimal number of tones grouped as a subchannel, the number of users that feed back for any subchannel and the number of bits used for quantization of CSI is found in this setting. The last part of this dissertation deals with the case when a downlink users's state information comprises both CSI and the number of packets in its receive buffer. With the advent of new applications, one of the primary applications supported in downlink cellular systems is streaming video. Quality of service (QoS) for streaming video entails data transmission to the mobile stations with limited latency and limited jitter, which maps to the number of yet-to-be-played packets in a mobile station's buffer, to always be above a certain minimum. This thesis solves the problem of optimal resource allocation in a downlink OFDMA system with this buffer constraint
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Understanding digital subscriber line technology
DSL advances
Alternative Names
Cioffi, John

Cioffi, John 1956-

Con Sioffi

John Cioffi American engineer

John Cioffi Amerikaans ingenieur

John Cioffi amerikansk ingeniør

John Cioffi amerikansk ingenjör

John Cioffi enginyer estatunidenc

John Cioffi ingeniero estadounidense

John Cioffi ingénieur américain

John Cioffi US-amerikanischer Elektroingenieur

جون سيوفي مهندس أمريكي

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English (35)

German (1)