McGill University

Displaying 1-40 of 101 results

  • White Papers // Feb 2014

    Associative Memories Based on Multiple-Valued Sparse Clustered Networks

    Associative memories are structures that store data patterns and retrieve them given partial inputs. Sparse Clustered Networks (SCNs) are recently-introduced binary-weighted associative memories that significantly improve the storage and retrieval capabilities over the prior state-of-the art. However, deleting or updating the data patterns result in a significant increase in the...

    Provided By McGill University

  • White Papers // Oct 2013

    Improving Sparse Associative Memories by Escaping from Bogus Fixed Points

    Associative memories are different from conventional memory systems in that they do not require explicit addresses to the information the authors are interested in. They store paired patterns. When an associative memory is given an input pattern as the probe, the content of the input itself addresses the paired output...

    Provided By McGill University

  • White Papers // Oct 2013

    A Massively Parallel Associative Memory Based on Sparse Neural Networks

    Associative memories store content in such a way that the content can be later retrieved by presenting the memory with a small portion of the content, rather than presenting the memory with an address as in more traditional memories. Associative memories are used as building blocks for algorithms within database...

    Provided By McGill University

  • White Papers // Oct 2012

    Bayesian Quantized Network Coding Via Belief Propagation

    In this paper, the authors propose an alternative for routing based packet forwarding, which uses network coding to increase transmission efficiency, in terms of both compression and error resilience. This non-adaptive encoding is called quantized network coding, which involves random linear mapping in the real field, followed by quantization to...

    Provided By McGill University

  • White Papers // Aug 2012

    Classical Codes for Quantum Broadcast Channels

    The authors discuss two techniques for transmitting classical information over quantum broadcast channels. The first technique is a quantum generalization of the superposition coding scheme for the classical broadcast channel. They use a quantum simultaneous non-unique decoder and obtain a simpler proof of the rate region recently published by Yard...

    Provided By McGill University

  • White Papers // Aug 2012

    Joint Utility Maximization in Two-Tier Networks by Distributed Pareto-Optimal Power Control

    This paper addresses the critical problem of interference management in two-tier networks, where the newly-deployed Femtocell UsErs (FUEs) operate in the licensed spectrum owned by the existing macrocell. A Pareto-optimal power-control algorithm is devised that jointly maximizes the utilities of both macrocell and femtocell networks while robustly guaranteeing the macrocell's...

    Provided By McGill University

  • White Papers // Jun 2012

    An Analysis of ZVP-Attack on ECC Cryptosystems

    Elliptic Curve Cryptography (ECC) is an efficient public cryptosystem with a short key size. For this reason it is suitable for implementing on memory-constraint devices such as smart cards, mobile devices, etc. However, these devices leak information about their private key through side channels (power consumption, electromagnetic radiation and timing,...

    Provided By McGill University

  • White Papers // May 2012

    Efficient Erasure Marking Technique for Interleaving Delay Reduction in DSL Systems Impaired by Impulse Noise

    Reed-Solomon (RS) coding and interleaving are usually combined to protect Digital Subscriber Line (DSL) systems against Impulse Noise (IN) but introducing a long delay. It is proved that interleaving delay can be significantly reduced by Error and Erasure Decoding (EED). This paper proposes an erasure marking technique to enhance the...

    Provided By McGill University

  • White Papers // May 2012

    On Optimal Input Distribution and Capacity Limit of Bernoulli-Gaussian Impulsive Noise Channels

    In this paper, the authors rigorously analyze the optimal input distribution and capacity of an additive Bernoulli-Gaussian (BG) Impulsive Noise (IN) channel in high and low input power regimes. First, they obtain an input distribution for which the channel output is Gaussian distributed. This distribution, if valid, shall result in...

    Provided By McGill University

  • White Papers // May 2012

    Impulse Noise Detection Techniques for Retransmission to Reduce Delay in DSL Systems

    To protect Digital Subscriber Loop (DSL) systems against Impulse Noise (IN), interleaving combined with Reed-Solomon (RS) coding has been used. Nevertheless, interleaving introduces a long delay. This paper considers retransmission instead of interleaving to reduce such delay and proposes an approach using the available RS decoding failure status to trigger...

    Provided By McGill University

  • White Papers // May 2012

    Cascaded Doubly-Selective Channel Estimation in Multi-Relay AF OFDM Transmissions

    This paper studies the problem of channel estimation in Amplify-and-Forward (AF) multi-relay transmissions over time- and frequency-selective (doubly selective) channels. To avoid two separate channel estimation processes of source-to-relay and relay-to-destination links, a cascaded doubly selective channel model is formulated to characterize the Source-to-Relay-to-Destination (SRD) channel. Time-varying SRD channel gains...

    Provided By McGill University

  • White Papers // May 2012

    On the Benefits of Non-Uniform Signaling in Chip-Asynchronous CDMA

    This paper explores chip-asynchronous CDMA transmission when single-user demodulation and decoding are used at the receiver. First, a chip-level channel model is presented to account for chip-asynchronism between different users. Using the model, the symmetric capacity of chip-asynchronous CDMA is investigated. Numerical results indicate that a sum rate of 2...

    Provided By McGill University

  • White Papers // May 2012

    EM-Based Joint Estimation and Detection for Multiple Antenna Cognitive Radios

    In this paper, the authors present an iterative spectrum sensing scheme for multiantenna assisted Cognitive Radio (CR) using the Expectation-Maximization (EM) algorithm. Considering a wideband frequency spectrum, the Secondary User (SU) performs an EM-based Joint Estimation and Detection (JED), where the channel coefficients and noise variance are estimated jointly with...

    Provided By McGill University

  • White Papers // May 2012

    Heterogeneous Space Switches for Power-Efficient Optical Interconnection Networks

    Space switches are the fundamental elements in single plane and multi-plane optical interconnection networks. This paper proposes a heterogeneous implementation of optical space switches based on two gating elements, amplifiers such as Semiconductor Optical Amplifier (SOA) and modulators such as Mach-Zehnder modulators. The heterogeneous implementation has the advantage of being...

    Provided By McGill University

  • White Papers // May 2012

    Capacity Limit of Static Single-Relay Amplify-and-Forward Channels

    In this paper, the authors establish in closed-form the capacity and characterize the optimal input covariance matrix at the source and the optimal power allocation scheme between source and relay for a half-duplex single-relay Amplify-and-Forward (AF) system with static channel gains. Different from Multiple-Input Multiple-Output (MIMO) systems, the channel matrix...

    Provided By McGill University

  • White Papers // May 2012

    Optimal Distributed Coding Schemes for Energy Efficiency in the Fading Relay Channel

    The authors propose three energy-optimal distributed schemes for the half-duplex relay channel with block fading to maintain a desired source rate. They consider both network energy consumption and consumption of the relay alone, assuming only local channel knowledge. Then, they combine both into a generalized distributed energy-efficient scheme. In these...

    Provided By McGill University

  • White Papers // May 2012

    Partial Decode-Forward Coding Schemes for the Gaussian Two-Way Relay Channel

    The authors design novel Partial Decode-Forward (PDF) schemes for the Gaussian two-way relay channel with direct link. Different from pure decode-forward, each user divides its message into two parts and the relay decodes only one part of each. The relay then generates its codeword as a function of the two...

    Provided By McGill University

  • White Papers // May 2012

    Optimal Power Adaption for NAF Relaying With Channel Side Information

    In this paper, the authors develop optimal power adaptation schemes by means of power amplification coefficients at the relay for the half-duplex single-relay Non-orthogonal Amplify-and-Forward (NAF) system with Channel Side Information (CSI) available at the relay. In particular, assuming that the relay has full knowledge of the channel gains, optimal...

    Provided By McGill University

  • White Papers // May 2012

    Joint Estimation of Time of Arrival and Channel Power Delay Profile for Pulse-Based UWB Systems

    Sub-Nyquist Maximum Likelihood (ML)-based Time Of Arrival (TOA) estimation methods for Ultra-WideBand (UWB) signals normally assume a priori knowledge of the UWB channel in the form of the Average Power Delay Profile (APDP). In practice however, and despite its importance, the APDP is not always available. To address this issue,...

    Provided By McGill University

  • White Papers // May 2012

    Topology-Aware VM Migration in Bandwidth Oversubscribed Datacenter Networks

    Virtualization can deliver significant benefits for cloud computing by enabling VM migration to improve utilization, balance load and alleviate hotspots. While several mechanisms exist to migrate VMs, few efforts have focused on optimizing migration policies in a multi-rooted tree datacenter network. The general problem has multiple facets, two of which...

    Provided By McGill University

  • White Papers // Apr 2012

    Asking and Answering Questions About Unfamiliar APIs: An Exploratory Study

    The increasing size of APIs and the increase in the number of APIs available imply developers must frequently learn how to use unfamiliar APIs. To identify the types of questions developers want answered when working with unfamiliar APIs and to understand the difficulty they may encounter answering those questions, the...

    Provided By McGill University

  • White Papers // Mar 2012

    Recovering Traceability Links Between an API and Its Learning Resources

    Large frameworks and libraries require extensive developer learning resources, such as documentation and mailing lists, to be useful. Maintaining these learning resources is challenging partly because they are not explicitly linked to the frameworks' API, and changes in the API are not reflected in the learning resources. Automatically recovering traceability...

    Provided By McGill University

  • White Papers // Mar 2012

    Restricted Isometry Property in Quantized Network Coding of Sparse Messages

    Efficient data gathering in sensor networks has been the topic of many research projects where different applications have been considered. One of the concerns in data gathering is to take care of inter-node redundancy during the transmission. When the knowledge of inter-node dependency is known at the encoders (i.e., sensor...

    Provided By McGill University

  • White Papers // Mar 2012

    Learning-Based Opportunistic Spectrum Access With Hopping Transmission Strategy

    This paper considers opportunistic spectrum access for Secondary Users (SUs) from an adaptive learning perspective. A SU dynamically hops over multiple idle frequency-slots of a licensed frequency band, each with an adaptive activity factor. Aiming to determine the optimal activity factors of SUs, an algorithm is developed, in which each...

    Provided By McGill University

  • White Papers // Mar 2012

    Sum-Rate Maximization in the Multicell MIMO Multiple-Access Channel With Interference Coordination

    This paper is concerned with the maximization of the weighted sum-rate in the multicell MIMO Multiple Access Channel (MAC). Considered is the multicell network operating on the same frequency channel with multiple Mobile Stations (MS) per cell. Assuming the interference coordination mode in the multicell network, each Base-Station (BS) only...

    Provided By McGill University

  • White Papers // Mar 2012

    Rate Maximization for Half-Duplex Multiple Access With Cooperating Transmitters

    The authors derive the optimal power allocation of a practical half-duplex scheme for the Multiple Access Channel with Transmitter Co-operation (MAC-TC). The system consists of two users in half-duplex mode communicating with one destination over a complex channel with additive white Gaussian noise. The transmission scheme is performed over 3...

    Provided By McGill University

  • White Papers // Jan 2012

    Proof Pearl: The Power of Higher-Order Encodings in the Logical Framework LF

    In this proof pearl, the authors demonstrate the power of higher-order encodings in the logical framework Twelf[PS99] by investigating proofs about an algorithmic specification of bounded subtype polymorphism, a problem from the POPLmark challenge [ABF+05]. Their encoding and representation of the problem plays to the strengths of the logical framework...

    Provided By McGill University

  • White Papers // Jan 2012

    Temporal Analysis of API Usage Concepts

    Software reuse through Application Programming Interfaces (APIs) is an integral part of software development. The functionality offered by an API is not always accessed uniformly throughout the lifetime of a client program. The authors propose Temporal API Usage Pattern Mining to detect API usage patterns in terms of their time...

    Provided By McGill University

  • White Papers // Jan 2012

    Analyzing Temporal API Usage Patterns

    Software reuse through Application Programming Interfaces (APIs) is an integral part of software development. As developers write client programs, their understanding and usage of APIs change over time. Can the people learn from long-term changes in how developers work with APIs in the lifetime of a client program? The authors...

    Provided By McGill University

  • White Papers // Dec 2011

    Partial Decode-Forward Binning Schemes for the Causal Cognitive Relay Channels

    The causal Cognitive Relay Channel (CRC) has two sender-receiver pairs, in which the second sender obtains information from the first sender causally and assists the transmission of both senders. In this paper, the authors study both the full- and half-duplex modes. In each mode, they propose two new coding schemes...

    Provided By McGill University

  • White Papers // Nov 2011

    Dynamic Control of Electricity Cost With Power Demand Smoothing and Peak Shaving for Distributed Internet Data Centers

    Internet based service providers, such as Amazon, Google, Yahoo, etc, build their Data Centers (IDC) across multiple regions to provide reliable and low latency of services to clients. Ever-increasing service demand, complexity of services and growing client population cause enormous power consumptions by these IDCs incuring a major part of...

    Provided By McGill University

  • White Papers // Nov 2011

    On Compress-Forward Without Wyner-Ziv Binning for Relay Networks

    Noisy network coding is recently proposed for the general multi-source network by Lim, Kim, El Gamal and Chung. This scheme builds on Compress-Forward (CF) relaying but involves three new ideas, namely no Wyner-Ziv binning, relaxed simultaneous decoding and message repetition. In this paper, using the two-way relay channel as the...

    Provided By McGill University

  • White Papers // Oct 2011

    Compress-Forward Without Wyner-Ziv Binning for the One-Way and Two-Way Relay Channels

    The authors consider the role of Wyner-Ziv binning in compress-forward for relay channels. In the one-way relay channel, they analyze a compress-forward scheme without Wyner-Ziv binning but with joint decoding of both the message and compression index. It achieves the same rate as the original compress-forward scheme with binning and...

    Provided By McGill University

  • White Papers // Oct 2011

    Distributed Dual Averaging for Convex Optimization Under Communication Delays

    In this paper, the authors extend and analyze the distributed dual averaging algorithm. They employ the fixed delay model introduced in and show that distributed dual averaging still converges in the presence of finite and fixed communication delays. In addition, using a different bounding technique than, for a fixed network...

    Provided By McGill University

  • White Papers // Sep 2011

    Approximating Signals Supported on Graphs

    In this paper, the authors investigate the notion of smoothness for signals supported on the vertices of a graph. They provide theoretical explanations when and why the Laplacian eigenbasis can be regarded as a meaningful "Fourier" transform of such signals. Moreover, they analyze the desired properties of the underlying graphs...

    Provided By McGill University

  • White Papers // Sep 2011

    Graph Spectral Compressed Sensing for Sensor Networks

    For many Wireless Sensor Network (WSN) applications, the signals measured are likely to be correlated either spatially or temporally; i.e., the authors can find an appropriate transform domain where the signals are compressible. WSNs are characterized by having simple battery-powered wireless nodes with limited energy and communication resources. In order...

    Provided By McGill University

  • White Papers // Sep 2011

    High-Level Design of Integrated Microsystems - Arithmetic Perspective

    Cyber-physical systems are characterized by tighter integration of embedded computer systems and the physical sensing and actuating devices. Integration of physical sensing and actuating interfaces into embedded systems presents a new set of high-level design and synthesis challenges. An important aspect of such integration is the explicit use of numerical...

    Provided By McGill University

  • White Papers // Aug 2011

    A Half-Duplex Relay Coding Scheme Optimized for Energy Efficiency

    The authors explore the issue of the network energy efficiency in relay channels. They first propose a half-duplex decode-forward coding scheme. They, then optimize the power allocation to minimize the total power consumption while maintaining a desired source rate. They show that this scheme significantly outperforms direct and two-hop transmissions....

    Provided By McGill University

  • White Papers // Aug 2011

    Decode-Forward and Compute-Forward Coding Schemes for the Two-Way Relay Channel

    The authors consider the full-duplex two-way relay channel with direct link between two users and propose two coding schemes: a partial decode-forward scheme, and a combined decode-forward and compute-forward scheme. Both schemes use rate-splitting and superposition coding at each user and generate code words for each node independently. When applied...

    Provided By McGill University

  • White Papers // Aug 2011

    Energy Minimization for the Half-Duplex Relay Channel With Decode-Forward Relaying

    The authors analyze coding for energy efficiency in the relay channel for a fixed source rate. They propose a comprehensive half-duplex decode-forward coding scheme and three optimal sets of power allocation, which respectively minimize the network, the relay and the source energy consumption. Analysis shows that minimizing the network energy...

    Provided By McGill University

  • White Papers // Apr 2007

    Best Practices In Network Audio

    The purpose of this paper is to inspire the reader and create a basis for further research and development that clearly defines the issues to potential funders from various arenas such as governments, foundations and corporations. Anyone who has seen a photo of the earth from space is immediately struck...

    Provided By McGill University

  • White Papers // Sep 2011

    High-Level Design of Integrated Microsystems - Arithmetic Perspective

    Cyber-physical systems are characterized by tighter integration of embedded computer systems and the physical sensing and actuating devices. Integration of physical sensing and actuating interfaces into embedded systems presents a new set of high-level design and synthesis challenges. An important aspect of such integration is the explicit use of numerical...

    Provided By McGill University

  • White Papers // Jul 2010

    Challenges in Verifying and Optimizing Fixed-Point Arithmetic-intensive Designs

    Arithmetic circuit plays a key role in Digital Signal Processing (DSP). A datapath is used to implement the specification usually represented as a polynomial. The two most important problems are verification and optimization of the arithmetic circuits. Circuit verification confirms whether the implementation can realize the specification with correct behavior...

    Provided By McGill University

  • White Papers // Apr 2007

    Hardware Assertion Checkers in On-line Detection of Faults in a Hierarchical-Ring Network-On-Chip

    In this paper, the authors present a methodology to use assertions in network-based designs to facilitate debugging and monitoring of System-on-Chips (SoCs). They rely on their assertion-checker generator (MBAC) to produce efficient RTL-level checkers from high-level temporal assertions, with optional debugging features. They further have built tools to encapsulate the...

    Provided By McGill University

  • White Papers // Oct 2013

    Improving Sparse Associative Memories by Escaping from Bogus Fixed Points

    Associative memories are different from conventional memory systems in that they do not require explicit addresses to the information the authors are interested in. They store paired patterns. When an associative memory is given an input pattern as the probe, the content of the input itself addresses the paired output...

    Provided By McGill University

  • White Papers // Oct 2013

    A Massively Parallel Associative Memory Based on Sparse Neural Networks

    Associative memories store content in such a way that the content can be later retrieved by presenting the memory with a small portion of the content, rather than presenting the memory with an address as in more traditional memories. Associative memories are used as building blocks for algorithms within database...

    Provided By McGill University

  • White Papers // Feb 2014

    Associative Memories Based on Multiple-Valued Sparse Clustered Networks

    Associative memories are structures that store data patterns and retrieve them given partial inputs. Sparse Clustered Networks (SCNs) are recently-introduced binary-weighted associative memories that significantly improve the storage and retrieval capabilities over the prior state-of-the art. However, deleting or updating the data patterns result in a significant increase in the...

    Provided By McGill University

  • White Papers // Apr 2010

    Endogenizing Growth Via A Lag For Apprenticing

    The authors take up a growth model with both skilled and unskilled labor, and a steady migration of some unskilled workers, who undertake apprenticing, to the skilled group of workers. Apprenticing involves a period of observing and thus labor output foregone. The time-out for observing represents a cost to the...

    Provided By McGill University

  • White Papers // Feb 2010

    AspectMATlab: An Aspect-Oriented Scientific Programming Language

    There has been relatively little work done in the compiler research community for incorporating aspect-oriented features in scientific and dynamic programming languages. MATLAB is a dynamic scientific programming language that is commonly used by scientists because of its convenient and high-level syntax for arrays, the fact that type declarations are...

    Provided By McGill University

  • White Papers // Mar 2011

    A Complete Descritpion of the UnPython and Jit4GPU Framework

    A new compilation framework enables the execution of numerical-intensive applications in an execution environment that is formed by multi-core Central Processing Units (CPUs) and Graphics Processing Units (GPUs). A critical innovation is the use of a variation of Linear Memory Access Descriptors (LMADs) to analyze loop nests and determine automatically...

    Provided By McGill University

  • White Papers // Jun 2011

    Throughput and Delay Analysis for Convergecast With MIMO in Wireless Networks

    This paper investigates throughput and delay based on a traffic pattern, called converge-cast, where each of the n nodes in the network acts as a destination with k randomly chosen sources corresponding to it. Adopting Multiple-Input-Multiple-Output (MIMO) technology, the authors devise two many-to-one cooperative schemes under converge-cast for both static...

    Provided By McGill University

  • White Papers // May 2011

    What Explains The German Labor Market Miracle In The Great Recession?

    Germany experienced an even deeper fall in GDP in the Great Recession than the United States with little employment loss. Employers' reticence to hire in the preceding expansion - associated in part with a lack of confidence it would last - contributed to an employment shortfall equivalent to 40 percent...

    Provided By McGill University

  • White Papers // Jan 2011

    Business Cycles And The Bankruptcy Code: A Structural Approach

    The authors develop a structural equilibrium model with business cycles and use it to examine the economic implications of voluntary filing for bankruptcy. They find that conflict of interests that arises from the voluntary filing option of causes higher ex-ante losses in firm value in recessions than in booms. These...

    Provided By McGill University

  • Case Studies // Jan 2010

    EBay - ECommerce Platform a Case Study in Scalability

    This case study speaks about the search and trading platform of eBay, an eCommerce giant. The company employs a vast multitude of platforms including PayPal and Skype. Most of these platforms have been obtained through acquisitions. Therefore, there is a risk of mismatch between these platforms. However, the paper researches...

    Provided By McGill University

  • White Papers // Jun 2011

    The Capacity of MIMO Channels With Per-Antenna Power Constraint

    The authors establish the optimal input signaling and the capacity of MIMO channels under per-antenna power constraint. While admitting a linear eigenbeam structure, the optimal input is no longer diagonalizable by the channel right singular vectors as with sum power constraint. They formulate the capacity optimization as an SDP problem...

    Provided By McGill University

  • White Papers // Aug 2009

    Capacity Impact of Location-Aware Cognitive Sensing

    The authors study Bayesian detection based cognitive sensing and analyze its impact on the capacity in various cases of location information. In a network of one primary and one cognitive user, the cognitive transmitter relies on information about the locations of the primary transmitter and the two receivers to design...

    Provided By McGill University

  • White Papers // Sep 2010

    Distributed Group Communication System for Mobile Devices Based on SMS

    This paper presents a group communication system for mobile devices, called DistributedGCS. Mobile communication is slow, expensive and suffers from occasional disconnections, especially when users are moving. DistributedGCS is based on SMS and enables group communication despite these restrictions. It provides all primitives needed for a chat application and handles...

    Provided By McGill University

  • White Papers // Dec 2011

    Partial Decode-Forward Binning Schemes for the Causal Cognitive Relay Channels

    The causal Cognitive Relay Channel (CRC) has two sender-receiver pairs, in which the second sender obtains information from the first sender causally and assists the transmission of both senders. In this paper, the authors study both the full- and half-duplex modes. In each mode, they propose two new coding schemes...

    Provided By McGill University

  • White Papers // Nov 2011

    On Compress-Forward Without Wyner-Ziv Binning for Relay Networks

    Noisy network coding is recently proposed for the general multi-source network by Lim, Kim, El Gamal and Chung. This scheme builds on Compress-Forward (CF) relaying but involves three new ideas, namely no Wyner-Ziv binning, relaxed simultaneous decoding and message repetition. In this paper, using the two-way relay channel as the...

    Provided By McGill University

  • White Papers // Aug 2011

    Energy Minimization for the Half-Duplex Relay Channel With Decode-Forward Relaying

    The authors analyze coding for energy efficiency in the relay channel for a fixed source rate. They propose a comprehensive half-duplex decode-forward coding scheme and three optimal sets of power allocation, which respectively minimize the network, the relay and the source energy consumption. Analysis shows that minimizing the network energy...

    Provided By McGill University

  • White Papers // Jul 2011

    Achievable Rates and Outer Bound for the Half-Duplex MAC With Generalized Feedback

    This paper provides comprehensive coding and outer bound for the half-duplex Multiple Access Channel with Generalized Feedback (MAC-GF). Two users communicate with one destination over a discrete memoryless channel using time division. Each transmission block is divided into 3 time slots with variable durations: the destination is always in receive...

    Provided By McGill University

  • White Papers // Nov 2009

    Location-Aware Cognitive Sensing for Maximizing Network Capacity

    The authors develop a closed-form optimal spectrum sensing threshold to maximize a cognitive network weighted sum capacity. In a one primary user and one cognitive user network, spatial location side information is used by the cognitive transmitter to adjust its sensing threshold accordingly. Numerical results show that, compared to another...

    Provided By McGill University

  • White Papers // Oct 2011

    Compress-Forward Without Wyner-Ziv Binning for the One-Way and Two-Way Relay Channels

    The authors consider the role of Wyner-Ziv binning in compress-forward for relay channels. In the one-way relay channel, they analyze a compress-forward scheme without Wyner-Ziv binning but with joint decoding of both the message and compression index. It achieves the same rate as the original compress-forward scheme with binning and...

    Provided By McGill University

  • White Papers // Aug 2011

    Decode-Forward and Compute-Forward Coding Schemes for the Two-Way Relay Channel

    The authors consider the full-duplex two-way relay channel with direct link between two users and propose two coding schemes: a partial decode-forward scheme, and a combined decode-forward and compute-forward scheme. Both schemes use rate-splitting and superposition coding at each user and generate code words for each node independently. When applied...

    Provided By McGill University

  • White Papers // Aug 2011

    A Half-Duplex Relay Coding Scheme Optimized for Energy Efficiency

    The authors explore the issue of the network energy efficiency in relay channels. They first propose a half-duplex decode-forward coding scheme. They, then optimize the power allocation to minimize the total power consumption while maintaining a desired source rate. They show that this scheme significantly outperforms direct and two-hop transmissions....

    Provided By McGill University

  • White Papers // Aug 2011

    MIMO Capacity With Per-Antenna Power Constraint

    In this paper, the authors consider the single-user MIMO channel with per-antenna power constraint. They formulate the capacity optimization problem with per-antenna constraint in the SDP framework and analyze its optimality conditions. They establish in closed-form the optimal input covariance matrix as a function of the dual variable. They, then...

    Provided By McGill University

  • White Papers // May 2011

    A Half-Duplex Cooperative Scheme With Partial Decode-Forward Relaying

    In this paper, the authors present a new cooperative communication scheme consisting of two users in half-duplex mode communicating with one destination over a discrete memoryless channel. The users encode messages in independent blocks and divide the transmission of each block into 3 time slots with variable durations. Cooperation is...

    Provided By McGill University

  • White Papers // Feb 2011

    Throughput-Optimal Half-Duplex Cooperative Scheme With Partial Decode-Forward Relaying

    The authors study a cooperative communication system consisting of two users in half duplex mode communicating with one destination over Additive White Gaussian Noise (AWGN). Cooperation is performed between the two users by partial decode-forward relaying over 3 time slots with variable duration. During the first two slots, each user...

    Provided By McGill University

  • White Papers // Feb 2011

    Energy-Efficient Schemes for On-Demand Relaying

    This paper approaches the fading relay channel from an energy consumption perspective and proposes an on-demand scheme based on superposition coding and Incremental Redundancy (IR). It aims at minimizing the relay's energy consumption, while maintaining a rate desired by the source. The source divides its message into two parts, which...

    Provided By McGill University

  • White Papers // May 2011

    Joint Typicality Analysis for Half-Duplex Cooperative Communication

    The authors propose a half-duplex cooperative scheme for a Discrete Memoryless Channel (DMC) consisting of two users communicating with one destination. The half-duplex constraint is satisfied by performing the communication over 3 time slots with variable durations in each code block. Each user alternatively transmits and receives during the first...

    Provided By McGill University

  • White Papers // Feb 2011

    Can Half-Duplex be Simply Derived From Full-Duplex Communications?

    The authors consider a discrete memoryless channel between two users and a destination in half-duplex mode implemented by time division. Each transmission block of length n is divided into 3 time slots with variable durations. During the first two time slots, each user alternatively transmits and receives, while during the...

    Provided By McGill University

  • White Papers // Feb 2010

    Interference and Outage Analysis in a Cognitive Radio Network With Beacon

    This paper presents a study on the interference caused by Secondary Users (SUs) due to miss-detection and its effects on the capacity-outage performance of the Primary User (PU) in a cognitive network with beacon. Investigation by simulation indicates that a Gamma distribution can be used to characterize the total interference...

    Provided By McGill University

  • White Papers // Nov 2010

    Efficient Decentralized Nonlinear Approximation Via Selective Gossip

    Recently, gossip algorithms have received much attention from the wireless sensor network community due to their simplicity, scalability and robustness. Motivated by applications such as compression and distributed transform coding, the authors propose a new gossip algorithm called Selective Gossip. Unlike the traditional randomized gossip which computes the average of...

    Provided By McGill University

  • White Papers // Feb 2011

    Sequential Monte Carlo Radio-Frequency Tomographic Tracking

    Radio Frequency (RF) tomographic tracking is the process of tracking moving targets by analyzing changes of attenuation in wireless transmissions. This paper presents a novel sequential Monte Carlo (SMC) method for RF tomographic tracking of a single target using a wireless sensor network. The algorithm incorporates on-line Expectation Maximization (EM)...

    Provided By McGill University

  • White Papers // Aug 2010

    Multi-Path Probabilistic Available Bandwidth Estimation Through Bayesian Active Learning

    Knowing the largest rate at which data can be sent on an end-to-end path such that the egress rate is equal to the ingress rate with high probability can be very practical when choosing transmission rates in video streaming or selecting peers in peer-to-peer applications. The authors introduce probabilistic available...

    Provided By McGill University

  • White Papers // May 2009

    Learning Minimum Delay Paths in Service Overlay Networks

    The authors propose a novel approach using active probing and learning techniques to track minimum delay paths for real-time applications in service overlay networks. Stochastic automata are used to probe paths in a decentralized, scalable manner. They propose four variations on active probing and learning strategies. It can be proved...

    Provided By McGill University

  • White Papers // Jul 2010

    Real-Time Multi-Path Tracking of Probabilistic Available Bandwidth

    Applications such as traffic engineering and network provisioning can greatly benefit from knowing, in real time, what is the largest input rate at which it is possible to transmit on a given path without causing congestion. The authors consider a probabilistic formulation for available bandwidth where the user specifies the...

    Provided By McGill University

  • White Papers // Apr 2011

    Efficient Delay-Tolerant Particle Filtering

    This paper proposes a novel framework for delay-tolerant particle filtering that is computationally efficient and has limited memory requirements. Within this framework the informativeness of a delayed (Out-Of-Sequence) Measurement (OOSM) is estimated using a lightweight procedure and uninformative measurements are immediately discarded. The framework requires the identification of a threshold...

    Provided By McGill University

  • White Papers // Oct 2010

    Distributed Auxiliary Particle Filters Using Selective Gossip

    This paper introduces a distributed auxiliary particle filter for target tracking in sensor networks. Nodes maintain a shared particle filter by coming to a consensus about the likelihoods associated with each particle using the selective gossip procedure. Selective gossip provides a mechanism to efficiently identify the particles with largest weights...

    Provided By McGill University

  • White Papers // Oct 2009

    Optimization and Analysis of Distributed Averaging With Memory

    This paper analyzes the rate of convergence of a distributed averaging scheme making use of memory at each node. In conventional distributed averaging, each node computes an update based on its current state and the current states of their neighbours. Previous work observed the trajectories at each node converge smoothly...

    Provided By McGill University