University of Toronto

Displaying 1-40 of 237 results

  • White Papers // Jun 2012

    Cost Efficient Datacenter Selection for Cloud Services

    Many cloud services nowadays are running on top of geographically distributed infrastructures for better reliability and performance. They need an effective way to direct the user requests to a suitable datacenter, in a cost efficient manner. Previous work focused mostly on the electricity cost of datacenters. The approaches favor datacenters...

    Provided By University of Toronto

  • White Papers // May 2012

    MixApart: Decoupled Analytics for Shared Storage Systems

    Data analytics and enterprise applications have very different storage functionality requirements. For this reason, enterprise deployments of data analytics are on a separate storage silo. This may generate additional costs and inefficiencies in data management, e.g., whenever data needs to be archived, copied, or migrated across silos. The authors introduce...

    Provided By University of Toronto

  • White Papers // May 2012

    Oruta: Privacy-Preserving Public Auditing for Shared Data in the Cloud

    With cloud storage services, it is commonplace for data to be not only stored in the cloud, but also shared across multiple users. However, public auditing for such shared data - while preserving identity privacy - remains to be an open challenge. In this paper, the authors propose the first...

    Provided By University of Toronto

  • White Papers // May 2012

    A General and Practical Datacenter Selection Framework for Cloud Services

    Many cloud services nowadays are running on top of geographically distributed infrastructures for better reliability and performance. They need an effective way to direct the user requests to a suitable datacenter, depending on factors including performance, cost, etc. Previous work focused on efficiency and invariably considered the simple objective of...

    Provided By University of Toronto

  • White Papers // Apr 2012

    Postcard: Minimizing Costs on Inter-Datacenter Traffic With Store-and-Forward

    It is typical for cloud providers to operate a number of geographically distributed datacenters, where inter-datacenter traffic constitutes a large portion of a cloud provider's traffic demand over the Internet. Though such inter-datacenter traffic incurs substantial operational costs that are charged by ISPs, it varies significantly across different overlay links,...

    Provided By University of Toronto

  • White Papers // Apr 2012

    Towards Optimal Capacity Segmentation With Hybrid Cloud Pricing

    Cloud resources are usually priced in multiple markets with different service guarantees. For example, Amazon EC2 prices virtual instances under three pricing schemes - the subscription option (a.k.a., Reserved Instances), the pay-as-you-go offer (a.k.a., On-Demand Instances), and an auction-like spot market (a.k.a., Spot Instances) - simultaneously. There arises a new...

    Provided By University of Toronto

  • White Papers // Mar 2012

    Bargaining Towards Maximized Resource Utilization in Video Streaming Datacenters

    Datacenters can be used to host large-scale video streaming services with better operational efficiency, as the multiplexing achieved by virtualization technologies allows different videos to share resources at the same physical server. Live migration of videos from servers that are overloaded to those that are under-utilized may be a solution...

    Provided By University of Toronto

  • White Papers // Mar 2012

    Distributional Measures of Semantic Distance: A Survey

    The ability to mimic human notions of semantic distance has widespread applications. Some measures rely only on raw text (distributional measures) and some rely on knowledge sources such as WordNet. Although extensive studies have been performed to compare WordNet-based measures with human judgment, the use of distributional measures as proxies...

    Provided By University of Toronto

  • White Papers // Feb 2012

    Maximizing Revenue With Dynamic Cloud Pricing: The Infinite Horizon Case

    The authors study the infinite horizon dynamic pricing problem for an infrastructure cloud provider in the emerging cloud computing paradigm. The cloud provider, such as Amazon, provides computing capacity in the form of virtual instances and charges customers a time-varying price for the period they use the instances. The provider's...

    Provided By University of Toronto

  • White Papers // Jan 2012

    Quality-Assured Cloud Bandwidth Auto-Scaling for Video-on-Demand Applications

    There has been a recent trend that Video-on-Demand (VoD) providers such as Netflix are leveraging resources from cloud services for multimedia streaming. In this paper, the authors consider the scenario that a VoD provider can make reservations for bandwidth guarantees from cloud service providers to guarantee the streaming performance in...

    Provided By University of Toronto

  • White Papers // Jan 2012

    A Theory of Cloud Bandwidth Pricing for Video-on-Demand Providers

    Current-generation cloud computing is offered with usage-based pricing, with no bandwidth capacity guarantees, which is however unappealing to bandwidth-intensive applications such as Video-on-Demand (VoD). The authors consider a new type of service where VoD providers, such as Netflix and Hulu, make reservations for bandwidth guarantees from the cloud at negotiable...

    Provided By University of Toronto

  • White Papers // Jan 2012

    Jointly Optimal Bit Loading, Channel Pairing and Power Allocation for Multi-Channel Relaying

    The authors aim to enhance the end-to-end rate of a general dual-hop relay network with multiple channels and finite modulation formats, by jointly optimizing channel pairing, power allocation, and integer bit loading. Such an optimization problem has both a discrete feasible region, due to the combinatoric nature of channel pairing,...

    Provided By University of Toronto

  • White Papers // Jan 2012

    Truthful Spectrum Auction Design for Secondary Networks

    Opportunistic wireless channel access by non-licensed users has emerged as a promising solution for addressing the bandwidth scarcity challenge. Auctions represent a natural mechanism for allocating the spectrum, generating an economic incentive for the licensed user to relinquish channels. A severe limitation of existing spectrum auction designs lies in the...

    Provided By University of Toronto

  • White Papers // Jan 2012

    Supporting Efficient Collective Communication in NoCs

    Across many architectures and parallel programming paradigms, collective communication plays a key role in performance and correctness. Hardware support is necessary to prevent important collective communication from becoming a system bottleneck. Support for multicast communication in Networks-on-Chip (NoCs) has achieved substantial throughput improvements and power savings. In this paper, the...

    Provided By University of Toronto

  • White Papers // Jan 2012

    ToX - The Toronto XML Engine

    The authors present ToX - the Toronto XML Engine - a repository for XML data and metadata, which supports real and virtual XML documents. Real documents are stored as files or mapped into relational or object databases, depending on their structuredness; indices are defined according to the storage method used....

    Provided By University of Toronto

  • White Papers // Jan 2012

    SFlow: Towards Resource-Efficient and Agile Service Federation in Service Overlay Networks

    Existing research work towards the composition of complex federated services has assumed that service requests and deliveries flow through a particular service path or tree. In this paper, the authors extend such a service model to a directed acyclic graph, allowing services to be delivered via parallel paths and interleaved...

    Provided By University of Toronto

  • White Papers // Jan 2012

    A High-Throughput Overlay Multicast Infrastructure With Network Coding

    Network coding has been recently proposed in information theory as a new dimension of the information multicast problem that helps achieve optimal transmission rate or cost. End hosts in overlay networks are natural candidates to perform network coding, due to its available computational capabilities. In this paper, the authors seek...

    Provided By University of Toronto

  • White Papers // Jan 2012

    Linear Processing for the Downlink in Multiuser MIMO Systems With Multiple Data Streams

    In this paper, the authors solve the problem of linear precoding for the downlink in multiuser Multiple-Input Multiple-Output (MIMO) systems. The transmitter and the receivers may be equipped with multiple antennas and each user may receive multiple data streams. Their objective is to jointly optimize the power allocation and transmit-receive...

    Provided By University of Toronto

  • White Papers // Jan 2012

    Automated Data Analysis Techniques for a Modern Silicon Debug Environment

    With the growing size of modern designs and more strict time-to-market constraints, design errors unavoidably escape pre-silicon verification and reside in silicon prototypes. As a result, silicon debug has become a necessary step in the digital integrated circuit design flow. Although embedded hardware blocks, such as scan chains and trace...

    Provided By University of Toronto

  • White Papers // Jan 2012

    From RTL to Silicon: The Case for Automated Debug

    Computer-aided design tools are continuously improving their scalability and efficiency to mitigate the high cost associated with designing and fabricating modern VLSI systems. A key step in the design process is the root-cause analysis of detected errors. Debugging may take months to close, introduce high cost and uncertainty ultimately jeopardizing...

    Provided By University of Toronto

  • White Papers // Jan 2012

    MANET Extensions to Ns2

    This is a set of software modules providing additional models for the simulation of multi-hop Mobile Ad hoc NETworks (MANETs) in the ns2 simulator. The authors provide implementations of the CM and Shell mobility models, and the AF and LOS radio propagation models described in. They also provide instrumentation tools...

    Provided By University of Toronto

  • White Papers // Dec 2011

    Distributed Optimal TXOP Control for Throughput Requirements in IEEE 802.11e Wireless LAN

    This paper designs a distributed Transmission OPportunity (TXOP) adaptation algorithm for IEEE802.11e Enhanced Distributed Channel Access (EDCA). Each node measures its throughput in a window and compares it with a target value. If the measured throughput is higher than the target value, the node reduces its TXOP, otherwise if the...

    Provided By University of Toronto

  • White Papers // Dec 2011

    Non-Solution Implications Using Reverse Domination in a Modern SAT-Based Debugging Environment

    With the growing complexity of VLSI designs, functional debugging has become a bottleneck in modern CAD flows. To alleviate this cost, various SAT-based techniques have been developed to automate bug localization in the RTL. In this paper, dominance relationships between circuit blocks have been recently shown to reduce the number...

    Provided By University of Toronto

  • White Papers // Dec 2011

    Leveraging Reconfigurability to Raise Productivity in FPGA Functional Debug

    The authors propose new hardware and software techniques for FPGA functional debug that leverage the inherent re-configurability of the FPGA fabric to reduce functional debugging time. The functionality of an FPGA circuit is represented by a programming bit-stream that specifies the configuration of the FPGA's internal logic and routing. The...

    Provided By University of Toronto

  • White Papers // Nov 2011

    On Error Tolerance and Engineering Change With Partially Programmable Circuits

    The growing size, density and complexity of modern VLSI chips are contributing to an increase in hardware faults and design errors in the silicon, decreasing manufacturing yield and increasing the design cycle. The use of Partially Programmable Circuits (PPCs) has been recently proposed for yield enhancement with very small overhead....

    Provided By University of Toronto

  • White Papers // Nov 2011

    Joint Power Control and Beamforming Codebook Design for MISO Channels under the Outage Criterion

    This paper investigates the joint design of power control and beamforming codebooks for limited-feedback Multiple-Input Single-Output (MISO) wireless systems. The problem is formulated as the minimization of the outage probability subject to the transmit power constraint and cardinality constraints on the beamforming and power codebooks. The authors show that the...

    Provided By University of Toronto

  • White Papers // Nov 2011

    Efficient Debugging of Multiple Design Errors

    After functional verification detects a failure, design debugging aims to find all locations in the design that could be responsible for the observed error. The task of debugging becomes more difficult in modern designs because of the presence of multiple design errors. Multiple design errors exponentially increase the solution space...

    Provided By University of Toronto

  • White Papers // Oct 2011

    Propelling SAT-Based Debugging Using Reverse Domination

    With the growing complexity of VLSI designs, functional debugging has become a bottleneck in modern CAD flows. To alleviate this cost, various SAT-based techniques have been developed to automate bug localization in the RTL. In this paper, dominance relationships between circuit blocks have been recently shown to reduce the number...

    Provided By University of Toronto

  • White Papers // Sep 2011

    Modeling on Quicksand

    Researchers studying the inter-domain routing system, its properties and new protocols, face many challenges in performing realistic evaluations and simulations. Modeling decisions with respect to AS-level topology, routing policies and traffic matrices are complicated by a dearth of ground truth for each of these components. Moreover, scalability is-sues arise when...

    Provided By University of Toronto

  • White Papers // Jul 2011

    Collaborative Caching for Video Streaming Among Selfish Wireless Service Providers

    Video streaming is now at the fingertips of mobile users with recent advances in wireless communications and mobile networking. Caching has been widely deployed by Wireless Service Providers (WSPs) to facilitate video content dissemination. Yet, capacity provisioning of cache servers is challenging given dynamic user demands and limited wireless bandwidth...

    Provided By University of Toronto

  • White Papers // Jul 2011

    YMMV: Multiple Session Multicast With MIMO

    Multicast is an important application in cellular networks. The 4G technologies, including WiMAX and LTE, invariably adopt Multiple-Input-Multiple-Output (MIMO) to facilitate spatial multiplexing and fundamentally increase channel capacity. However, state-of-the-art multicast protocols are designed to perform in single-hop mode with a single session, leading to under-utilization of the scarce spectrum...

    Provided By University of Toronto

  • White Papers // Jul 2011

    Completion Delay Reduction in Lossy Feedback Scenarios for Instantly Decodable Network Coding

    In this paper, the authors study the effect of packet feedback loss events on the broadcast completion delay performance of instantly decodable network coding. These feedback loss events result in a continuous lack of knowledge about the reception status at different subsets of receivers. This lack of knowledge creates a...

    Provided By University of Toronto

  • White Papers // Jul 2011

    Jointly Optimal Channel Pairing and Power Allocation for Multi-Channel Multi-Hop Relaying

    The authors study the problem of channel pairing and power allocation in a multi-channel multi-hop relay network to enhance the end-to-end data rate. Both Amplify-and-Forward (AF) and Decode-and-Forward (DF) relaying strategies are considered. Given fixed power allocation to the channels, they show that channel pairing over multiple hops can be...

    Provided By University of Toronto

  • White Papers // Jun 2011

    Latch-Based Performance Optimization for FPGAs

    The authors explore using pulsed latches for timing optimization - a first in the FPGA community. Pulsed latches are transparent latches driven by a clock with a non-standard (non-50%) duty cycle. They exploit existing functionality within commercial FPGA chips to implement latch-based optimizations that do not have the power or...

    Provided By University of Toronto

  • White Papers // Jun 2011

    Usury, Calvinism, And Credit In Protestant England: From The Sixteenth Century To The Industrial Revolution

    This paper analyzes the impact of Protestantism on interest rates in England from the 16th century to the Industrial Revolution. One of many myths about the usury doctrine - the prohibition against demanding anything above the principal in a loan (mutuum) - is that it ceased to be observed in...

    Provided By University of Toronto

  • White Papers // Jun 2011

    Low-Cost Hardware Profiling of Run-Time and Energy in FPGA Embedded Processors

    Field-Programmable Gate Arrays (FPGAs) are a widely used technology in the design of embedded systems due to their improving speed, density and power, steadily decreasing cost, and their programmability which reduces a product's time-to-market. The advent of FPGA soft processors permits the creation of hybrid systems within a single FPGA...

    Provided By University of Toronto

  • White Papers // Jun 2011

    Reducing FPGA Router Run-Time Through Algorithm and Architecture

    The authors propose a new FPGA routing approach that, when combined with a low-cost architecture change, results in a 34% reduction in router run-time, at the cost of a 3% area overhead, with no increase in critical path delay. Their approach begins with traditional Path-Finder-style routing, which they run on...

    Provided By University of Toronto

  • White Papers // Jun 2011

    Canadian Monetary Policy And Real And Nominal Exchange Rates [Revised]

    This study undertakes an analysis of the relationship between Canadian monetary policy and the movements of Canada's real and nominal exchange rates with respect to the United States and, less directly, with respect to the rest of the world. It encompasses, extends and broadens a range of more narrowly-focused rigorous...

    Provided By University of Toronto

  • White Papers // Jun 2011

    Linking Semistructured Data on the Web

    Many Web data sources and APIs make their data available in XML, JSON, or a domain-specific semi-structured format, with the goal of making the data easily accessible and usable by Web application developers. Although such data formats are more machine-processable than pure text documents, managing and analyzing such data in...

    Provided By University of Toronto

  • White Papers // May 2011

    Non-Coherent Capacity of Secret-Key Agreement With Public Discussion

    The authors study the non-coherent capacity of secret-key agreement with public discussion over i.i.d. Rayleigh Fading wireless channels, where neither the sender nor the receivers have access to instantaneous Channel State Information (CSI). They present two results. At high Signal-to-Noise Ratio (SNR), the secret-key capacity is bounded in SNR, regardless...

    Provided By University of Toronto

  • White Papers // Nov 2008

    ? Network-Independent Partner Selection And The Evolution Of Innovation Networks ?

    Empirical research on strategic alliances has focused on the idea that alliance partners are selected on the basis of social capital considerations. In this paper the authors emphasize instead the role of complementary knowledge stocks (broadly defined) in partner selection, arguing not only that knowledge complementarity should not be overlooked,...

    Provided By University of Toronto

  • White Papers // Aug 2010

    Group Strategyproof Multicast in Wireless Networks

    The authors study the dissemination of common information from a source to multiple nodes within a multihop wireless network, where nodes are equipped with uniform omni-directional antennas and have a fixed cost per packet transmission. While many nodes may be interested in the dissemination service, their valuation or utility for...

    Provided By University of Toronto

  • White Papers // Sep 2008

    A Constant Bound on Throughput Improvement of Multicast Network Coding in Undirected Networks

    Recent research in network coding shows that, joint consideration of both coding and routing strategies may lead to higher information transmission rates than routing only. A fundamental question in the field of network coding is: How large can the throughput improvement due to network coding be? In this paper, the...

    Provided By University of Toronto

  • White Papers // Mar 2009

    Why Are Peers Less Stable in Unpopular P2P Streaming Channels?

    In large-scale P2P live streaming systems, it is shown that peers in an unpopular channel often experience worse streaming quality than those in popular channels. In this paper, by analyzing 130 GB worth of traces from a large-scale P2P streaming system, UUSee, the authors observe that a large number of...

    Provided By University of Toronto

  • White Papers // Jan 2009

    Distilling Superior Peers in Large-Scale P2P Streaming Systems

    In large-scale Peer-To-Peer (P2P) live streaming systems with a limited supply of server bandwidth, increasing the amount of upload bandwidth supplied by peers becomes critically important to the "Well being" of streaming sessions in live channels. Intuitively, two types of peers are preferred to be kept up in a live...

    Provided By University of Toronto

  • White Papers // Jul 2009

    Programming With Quantum Communication

    The term quantum communication refers to the process of transferring a quantum state between distinct physical locations. There are two ways of accomplishing this task. The first one is analogous to classical communication and involves sending a quantum bit over a quantum communication channel (just as classical communication is associated...

    Provided By University of Toronto

  • White Papers // Jan 2011

    Scaling and Continuous Availability in Database Server Clusters Through Multiversion Replication

    In this paper, the authors study replication techniques for scaling and continuous operation for a dynamic content server. The focus is on supporting transparent and fast reconfiguration of its database tier in case of overload or failures. They show that the data persistence aspects can be decoupled from reconfiguration of...

    Provided By University of Toronto

  • White Papers // Sep 2010

    Revisiting Defenses Against Large-Scale Online Password Guessing Attacks

    Brute force and dictionary attacks on password-only remote login services are now widespread and ever increasing. Enabling convenient login for legitimate users while preventing such attacks is a difficult problem. Automated Turing Tests (ATTs) continue to be an effective, easy-to-deploy approach to identify auto-mated malicious login attempts with reasonable cost...

    Provided By University of Toronto

  • White Papers // Jun 2009

    Face Recognition With Biometric Encryption for Privacy-Enhancing Self-Exclusion

    Face recognition has been employed in various security-related applications such as surveillance, mugshot identification, e-passport, and access control. Despite its recent advancements, privacy concern is one of several issues preventing its wider deployment. In this paper, the authors address the privacy concern for a self-exclusion scenario of face recognition, through...

    Provided By University of Toronto

  • White Papers // Nov 2009

    Delay Bounds for Networks With Heavy-Tailed and Self-Similar Traffic

    The authors provide upper bounds on the end-to-end backlog and delay in a network with heavy-tailed and self-similar traffic. The analysis follows a network calculus approach where traffic is characterized by envelope functions and service is described by service curves. A key contribution of this paper is the derivation of...

    Provided By University of Toronto

  • White Papers // Jan 2010

    Understanding Latent Sector Errors and How to Protect Against Them

    Latent Sector Errors (LSEs) refer to the situation where particular sectors on a drive become inaccessible. LSEs are a critical factor in data reliability, since a single LSE can lead to data loss when encountered during RAID reconstruction after a disk failure. LSEs happen at a significant rate in the...

    Provided By University of Toronto

  • White Papers // Jun 2011

    Linking Semistructured Data on the Web

    Many Web data sources and APIs make their data available in XML, JSON, or a domain-specific semi-structured format, with the goal of making the data easily accessible and usable by Web application developers. Although such data formats are more machine-processable than pure text documents, managing and analyzing such data in...

    Provided By University of Toronto

  • White Papers // Aug 2009

    Indeterminacy Of Competitive Equilibrium With Risk Of Default

    The authors prove indeterminacy of competitive equilibrium in sequential economies, where limited commitment requires the endogenous determination of solvency constraints preventing debt repudiation (Alvarez and Jermann). In particular, they show that, for any arbitrary value of social welfare in between autarchy and (constrained) optimality, there exists an equilibrium at which...

    Provided By University of Toronto

  • White Papers // May 2011

    Learning Better Image Representations Using 'Flobject Analysis'

    Unsupervised learning can be used to extract image representations that are useful for various and diverse vision tasks. After noticing that most biological vision systems for interpreting static images are trained using disparity information, the authors developed an analogous framework for unsupervised learning. The output of their method is a...

    Provided By University of Toronto

  • White Papers // Apr 2011

    On Deep Generative Models With Applications to Recognition

    The most popular way to use probabilistic models in vision is first to extract some descriptors of small image patches or object parts using well-engineered features, and then to use statistical learning tools to model the dependencies among these features and eventual labels. Learning probabilistic models directly on the raw...

    Provided By University of Toronto

  • White Papers // May 2008

    Improving Forecasts Of Inflation Using The Term Structure Of Interest Rates

    Many pricing models imply that nominal interest rates contain information on inflation expectations. This has lead to a large empirical literature that investigates the use of interest rates as predictors of future inflation. Most of these focus on the Fisher hypothesis in which the interest rate maturity matches the inflation...

    Provided By University of Toronto

  • White Papers // Aug 2010

    Awareness Requirements for Adaptive Systems

    Recently, there has been a growing interest in self-adaptive systems. Roadmap papers in this area point to feedback loops as a promising way of operationalizing adaptivity in such systems. In this paper, the authors present a new type of requirement - called Awareness Requirement - that can refer to other...

    Provided By University of Toronto

  • White Papers // Jan 2009

    The Secret Life of Bugs: Going Past the Errors and Omissions in Software Repositories

    Every bug has a story behind it. The people that discover and resolve it need to coordinate, to get information from documents, tools, or other people, and to navigate through issues of accountability, ownership, and organizational structure. This paper reports on a field study of coordination activities around bug fixing...

    Provided By University of Toronto

  • White Papers // Sep 2010

    Inequality And Growth In A Knowledge Economy

    The authors develop a two sector growth model to understand the relation between inequality and growth. Agents, who are endowed with different levels of knowledge, select either into a retail or a manufacturing sector. Agents in the manufacturing sector match to carry out production. A by-product of production is creation...

    Provided By University of Toronto

  • White Papers // Jan 2009

    Wake Up And Smell The Ginseng: International Trade And The Rise Of Incremental Innovation In Low-Wage Countries

    Increasingly, a small number of low-wage countries such as China and India are involved in incremental innovation. That is, they are responsible for resolving production-line bugs and suggesting product improvements. The authors provide evidence of this new phenomenon and develop a model in which there is a transition from old-style...

    Provided By University of Toronto

  • White Papers // Nov 2010

    Optimal Channel Pairing and Power Allocation for Multi-Channel Multi-Hop Relay Networks

    The authors study the problem of channel pairing and power allocation in a multi-channel, multi-hop relay network to enhance the end-to-end data rate. OFDM-based relays are used as an illustrative example, and the amplify-and-forward and decode-and-forward relaying strategies are considered. Given fixed power allocation to the OFDM subcarriers, they observe...

    Provided By University of Toronto

  • White Papers // Jan 2011

    Optimal Channel Assignment and Power Allocation for Dual-Hop Multi-Channel Multi-User Relaying

    The authors consider the problem of jointly optimizing channel pairing, channel-user assignment, and power allocation in a single-relay multiple-access system. The optimization objective is to maximize the weighted sum-rate under total and individual power constraints on the transmitters. By observing the special structure of a three-dimensional assignment problem derived from...

    Provided By University of Toronto

  • White Papers // Mar 2010

    Optimal Control of Constrained Cognitive Radio Networks With Dynamic Population Size

    In this paper, the authors consider the problem of optimal control for throughput utility maximization in cognitive radio networks with dynamic user arrivals and departures. The cognitive radio network considered in this paper consists of a number of heterogeneous sub-networks. These sub-networks may be power-constrained and are required to operate...

    Provided By University of Toronto

  • White Papers // Jun 2010

    Partial Zero-Forcing Precoding for the Interference Channel With Partially Cooperating Transmitters

    A communication model is considered in which the classic two-user Gaussian interference channel is augmented by noiseless rate-limited digital conferencing links between the transmitters. The authors propose a partial zero-forcing pre-coding strategy based on a shared-private rate splitting scheme at the transmitter, in which each transmitter communicates part of its...

    Provided By University of Toronto

  • White Papers // Mar 2010

    On the Symmetric Capacity of the K-User Symmetric Cyclic Gaussian Interference Channel

    The capacity region of Gaussian interference channel in the weak interference regime is an open problem. Recently, Etkin, Tse and Wang derived an outer bound for the two-user Gaussian interference channel and proved that a simple Han-Kobayashi signaling scheme can achieve within one bit of the capacity region for all...

    Provided By University of Toronto

  • White Papers // Feb 2010

    High Resolution Channel Quantization Rules for Multiuser Spatial Multiplexing Systems

    This paper addresses the optimal channel quantization codebook design for limited feedback multiple-antenna multiuser channels. The base station is equipped with M antennas and serves M single-antenna users, which share a total feedback rate B. The authors assume real space channels for convenience; the extension of the analysis to complex...

    Provided By University of Toronto

  • White Papers // Jan 2009

    Gaussian Z-Interference Channel With a Relay Link: Type II Channel and Sum Capacity Bound

    This paper studies the Gaussian Z-interference channel with a rate-limited digital relay link from one receiver to the other receiver. In a companion paper, the authors dealt with the Type I channel, where the relay link goes from the interference-free receiver to the interfered receiver. It was shown that in...

    Provided By University of Toronto

  • White Papers // Dec 2009

    Throughput Analysis of Multiple Access Relay Channel Under Collision Model

    Despite much research on the throughput of relaying networks under idealized interference models, many practical wireless networks rely on physical-layer protocols that preclude the concurrent reception of multiple transmissions. In this paper, the authors develop analytical frameworks for the uplink of a multi-source single-channel relay-aided wireless system where transmissions are...

    Provided By University of Toronto

  • White Papers // May 2009

    Liquidity, Volume, And Price Behavior: The Impact Of Order Vs. Quote Based Trading

    The authors provide a three way theoretical comparison of dealer, limit order and hybrid markets and analyze the impact that the organization of trading has on volume, liquidity, and price efficiency. They find, in particular, that trading volume is highest in the limit order market and lowest in the dealer...

    Provided By University of Toronto

  • White Papers // Feb 2011

    Multicell Interference Mitigation With Joint Beamforming and Common Message Decoding

    Conventional wireless cellular systems treat out-of-cell interference as noise. This paper proposes methods and examines the benefit of designing decodable interference signals, whereby a transmitter may split its message into a common and a private part, and the common message may be decoded and subtracted by users in adjacent cells....

    Provided By University of Toronto

  • White Papers // Feb 2011

    Interference Mitigation Via Joint Detection

    This paper addresses the design of optimal and near-optimal detectors in an interference channel with fading and with Additive White Gaussian Noise (AWGN), where the transmitters employ discrete modulation schemes as in practical communication scenarios. The conventional detectors typically either ignore the interference or successively detect and then cancel the...

    Provided By University of Toronto

  • White Papers // Sep 2010

    Bit Allocation Law for Multi-Antenna Channel Feedback Quantization: Single-User Case

    This paper studies the design and optimization of a limited feedback single-user system with multiple-antenna transmitter and single-antenna receiver. The design problem is cast in form of the minimizing the average transmission power at the base station subject to the user's outage probability constraint. The optimization is over the user's...

    Provided By University of Toronto

  • White Papers // Apr 2011

    District: Embracing Local Markets in Truthful Spectrum Double Auctions

    The recent explosive growth of wireless networks, with their ever-growing demand for radio spectrum, has exacerbated the problem of spectrum scarcity. Such scarcity, however, is not an outcome of exhausted physical spectrum, but a result of inefficient channel utilization due to existing policies that channels are licensed to their authorized...

    Provided By University of Toronto

  • White Papers // Jan 2011

    Effect of Relaying on Capacity Improvement in Wireless Local Area Networks

    Wireless relay nodes can improve the capacity of wireless networks. In this paper, the authors integrate wireless relay nodes to the infrastructure of a Wireless Local Area Network (WLAN). In particular, they investigate the effect of different relay strategies and optimal utilization of a fixed number of immobile relay nodes,...

    Provided By University of Toronto

  • White Papers // Jan 2011

    The RRMS Protocol: Fair Medium Access in Ad Hoc Networks

    MAC level protocols in ad hoc networks must overcome the decentralized nature of the network and provide adequate throughput and fairness. This paper presents a new MAC protocol named Randomly Ranked Mini Slots (RRMS), which provides throughput at near channel capacity and good fairness as defined by a common sense...

    Provided By University of Toronto

  • White Papers // Jan 2011

    An Efficient Algorithm for the Optimal Placement of Wireless Extension Points in Rectilineal Wireless Local Area Networks

    Wireless Extension Points (EPs) are immobile devices that relay data between the Access Point and the mobile users in a heterogeneous Wireless Local Area Network (WLAN). In this paper, the authors investigate the optimal placement of EPs such that the throughput capacity of a rectilineal WLAN is maximized. Two channel...

    Provided By University of Toronto

  • White Papers // Sep 2009

    On Minimizing Multicast Completion Delay for Instantly Decodable Network Coding

    In this paper, the authors consider the problem of minimizing the mean completion delay in wireless multicast for instantly decodable network coding. They first formulate the problem as a Stochastic Shortest Path (SSP) problem. Although finding the optimal selection policy using SSP is intractable, they use this formulation to draw...

    Provided By University of Toronto

  • White Papers // Sep 2009

    Accelerometer-Based Gesture Recognition Via Dynamic - Time Warping, Affinity Propagation, & Compressive Sensing

    The authors propose a gesture recognition system based primarily on a single 3-axis accelerometer. The system employs dynamic time warping and affinity propagation algorithms for training and utilizes the sparse nature of the gesture sequence by implementing compressive sensing for gesture recognition. A dictionary of 18 gestures or classes is...

    Provided By University of Toronto

  • White Papers // Sep 2009

    Compressive Detection For wide-Band Spectrum Sensing

    In this paper the authors propose a novel wide-band spectrum sensing scheme using compressive sensing. The wide-band signal is fed into a number of wide-band filters and the outputs of the filters are used to reconstruct the vector of channel energies through the compressive sensing's ??"1 norm minimization. An energy...

    Provided By University of Toronto

  • White Papers // Sep 2008

    Real-Time Communications in Large-Scale Wireless Networks

    There is an emerging need for realizing real-time Quality of Service (QoS) over multihop wireless communications in large-scale wireless networks. The applications can include wireless mesh infrastructure for broadband Internet access supporting multimedia services, visual sensor networks for surveillance, and disaster-relief networks. However, a number of challenges still exist as...

    Provided By University of Toronto