Institute of Electrical and Electronics Engineers

Displaying 161-200 of 8178 results

  • White Papers // Nov 2012

    Optimal D2D User Allocation over Multi-Bands under Heterogeneous Networks

    This paper analyzes the optimal D2D user allocation over multi-bands in the heterogeneous networks. The heterogeneous networks contain one or several cellular systems and D2D communication shares uplink resource with them. By allocating D2D users on different bands, it can reduce the interference between D2D and cellular systems and improve...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Nov 2012

    Energy-based Cooperative Spectrum Sensing for Emergency Communications over Fading Channels in Cognitive Radio Public Safety Networks

    From the perspective of interoperability, Cognitive Radio (CR) is widely studied as an emerging alternative for public safety communications. Spectrum sensing is one of key functionalities enabling the opportunistic spectrum utilization for CR systems. The energy-based cooperative spectrum sensing is mostly adopted in current CR prototype systems due to the...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Nov 2012

    Fairness and Network Capacity Trade-off in P2P IEEE 802.22 Networks

    Wireless Regional Area Networks(WRAN), IEEE 802.22 standard, adopts a centralized cellular topology including Base Station (BS) and Customer-Premise Equipments (CPEs). However this may lead to limited network capacity, since every CPE needs to communicate to the BS and only one channel can be used to communicate in the whole cell...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Nov 2012

    Distributed Sensing of Spectrum Occupancy and Interference in Outdoor 2.4 GHz Wi-Fi Networks

    A spectrum monitoring campaign was launched in an outdoor urban radio environment to investigate the potential deployment of Cognitive Radio (CR) Wi-Fi networks in the 2.4 GHz ISM band. The campaign used a CR learning platform with 4, 8, and 16 sensors. This paper presents Wi-Fi spectrum occupancy and interference...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Nov 2012

    Improved Active Interference Cancellation for Sidelobe Suppression in Cognitive OFDM Systems

    Active Interference Cancellation (AIC) is known to be a very effective technique for reducing the interference of OFDM side-lobes to primary licensed users in cognitive OFDM systems. However, AIC has some shortcomings such as high computational complexity and spectrum overshoot on the cancellation sub-carriers. Spectrum overshoot is mainly caused due...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Nov 2012

    Interference Alignment-Like Precoder Design in Multi-Pair Two-Way Relay Cognitive Radio Networks

    In this paper, the authors design relay precoder in a MIMO cognitive radio network where two-way transmission of multiple secondary user pairs occurs concurrently with primary network's transmission. They propose an interference alignment like precoder design which jointly aligns the direction of interference and the desired signal while interference to...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Nov 2012

    Suppressing the Out-of-band Power Radiation in Multi-carrier Systems: A Comparative Study

    As of today, Orthogonal Frequency-Division Multiplexing (OFDM) has been the dominant technique in broadband transmission systems. However, for the application in cognitive radios, the side lobes of rectangularly pulsed OFDM signals must be well suppressed to satisfy the rigorous spectral masks. In this paper, Filter-Bank based Multi-Carrier (FBMC) transmission, which...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Nov 2012

    A Quadrature Signaling based Cooperative Scheme for Cognitive Radio Networks

    A two-phase cooperative framework in Cognitive Radio Networks (CRNs), whereby the Secondary Users (SUs) can fully exploit the transmission opportunities through cooperation with Primary Users (PUs), is proposed. Specifically, the SU cooperates with the active PU to improve the PU's utility. As a reward, the period of time when the...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Nov 2012

    Enhanced Spectrum Awareness with Extended Information Carried on Embedded Cyclostationary Signatures for Cognitive Radio

    Embedded Cyclostationary Signature (ECS) was recently developed as a useful tool for facilitating detection, classification, frequency acquisition and spectrum rendezvous for wireless devices or networks. In this paper, the authors present a novel technique for conveying extended information on ECS in multi-carrier signals. The extended information may include device/network identity,...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Nov 2012

    Real-time Cyclostationary Analysis for Cognitive Radio via Software Defined Radio

    Cyclostationary analysis such as Spectral Correlation Function (SCF) and Spectral Coherence Function (SOF) has been accepted as an important tool in signal detection and Radio Frequency (RF) parameter estimation in cognitive radios. However, cyclostationary analysis requires extremely high resolution to fully observe the cyclic frequency features, leading to very high...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Nov 2012

    Eigenvalue-based Cyclostationary Spectrum Sensing Using Multiple Antennas

    In this paper, the authors propose a signal-selective spectrum sensing method for cognitive radio networks and specifically targeted for receivers with multiple-antenna capability. This method is used for detecting the presence or absence of primary users based on the eigenvalues of the cyclic covariance matrix of received signals. In particular,...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Nov 2012

    Comparison of Cooperative Spectrum Sensing Strategies in Distributed Cognitive Radio Networks

    Cooperative spectrum sensing has been proposed to significantly improve spectrum sensing accuracy by taking advantage of the cooperation among Secondary Users (SUs), but also this incurs some sensing cost. In this paper, the authors present a cooperative spectrum sensing model with consideration to spectrum sensing cost in distributed cognitive radio...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Nov 2012

    The Effect of Additional Statistical Side Information on Multiple Antenna Spectrum Sensing

    In this paper, the authors consider the problem of multiple antenna spectrum sensing in Cognitive Radios (CR) when some or all parameters are unknown. The Generalized Likelihood Ratio (GLR) test is the convectional method to solve the composite hypothesis testing problem in which the detection and estimation sub-problems are considered...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Nov 2012

    A Group Testing Based Spectrum Hole Search Using a Simple Sub-Nyquist Sampling Scheme

    In this paper, the authors consider the problem of finding a spectrum hole of a specified bandwidth in a given wide band of interest. They propose a new, simple and easily implementable sub-Nyquist sampling scheme for signal acquisition and a spectrum hole search algorithm that exploits sparsity in the primary...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Nov 2012

    Incremental Relaying Transmissions with Relay Selection in Cognitive Radio Networks

    In this paper, the authors investigate and evaluate the performance of incremental relaying and relay selection, when used in the context of cognitive radio networks. Assuming that a number of cognitive radio relay nodes N (N-2) are co-located with simultaneous primary and secondary transmissions, the "Best" relays are chosen to...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Nov 2012

    Secure MISO Cognitive Radio System with Perfect and Imperfect CSI

    In cognitive Radio (CR) systems, harmful interference from the secondary system degrades the data rate of the primary system. However, this interference may be beneficial to the primary system in terms of the secrecy rate, when unauthorized users eavesdrop on the primary link. This paper explores Multiple-Input Single-Output (MISO) CR...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Nov 2012

    On the User Scheduling in Cognitive Radio MIMO Networks

    The cognitive radio technology allows the design of dynamic spectrum sharing techniques where unlicensed secondary users can use frequency bands owned by license primary holders. Thus, this emerging technology is regarded as the ideal candidate that can enhance the efficiency of spectrum usage for the next generation of wireless communication...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Nov 2012

    Modeling and Performance Analysis of Device Discovery in Bluetooth Low Energy Networks

    BlueTooth Low Energy (BT LE) is a low power air interface technology recently released by the BlueTooth Special Interest Group (BT SIG). As a promising radio, BT LE realizes many designing features to fulfill foreseeable requirements of short range communication, such as fast device discovery, power saving transmitting, encryption and...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Nov 2012

    Improved Energy Detection with Interference Cancellation in Heterogeneous Cognitive Wireless Networks

    Energy detection is the most popular method among spectrum sensing techniques due to its low implementation complexity. However, its performance will be severely degraded by the interference from other Secondary Users (SUs). In this paper, the authors first analyze the interference impact on the energy detection in a Heterogeneous Cognitive...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Nov 2012

    Energy Saving through a Learning Framework in Greener Cellular Radio Access Networks

    Recent papers have validated the possibility of energy efficiency improvement in Radio Access Networks (RAN), depending on dynamically turn on/off some Base Stations (BSs). In this paper, the authors extend the research over BS switching operation, matching up with traffic load variations. However, instead of depending on the predicted traffic...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Nov 2012

    Multicast Throughput Optimization and Fair Spectrum Sharing in Cognitive Radio Networks

    By enabling opportunistic Secondary Users' (SUs) usage of licensed spectrum, Cognitive Radio (CR) technology notably improves spectrum utilization. However, the fundamental multicast throughput optimization problem in Cognitive Radio Networks (CRNs) is still under-explored. Considering spectrum availability and sharing fairness, in this paper, the authors propose a cross-layer approach to maximize...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Nov 2012

    Rateless Code Based Opportunistic Multicasting over Cognitive Radio Networks

    Cognitive Radio (CR) represents an exciting new paradigm on spectrum utilization and potentially more bandwidth for exploding multimedia traffic. The authors focus on the layer encoded video multicast problem over CR and contribute an opportunistic multicasting framework, based on rateless Forward Error Correction (FEC) codes, a mechanism for adaptation of...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Nov 2012

    Multi-path Routing in Cognitive Radio Networks for Multimedia Communication using Sample Division Multiplexing

    The authors propose a novel scheme for multi-path routing in a Cognitive Radio Network (CRN) for multimedia communication, even when a contiguous band of required width is not available for any hop in the route. The proposed scheme is based on an extension of the idea of Sample Division Multiplexing...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Nov 2012

    Procedure to Build Interference Map in Peer to Peer IEEE 802.22 Networks

    Peer to Peer Wireless Regional Area Network (P2PWRAN) is proposed as an extension to support peer to peer communication based on IEEE 802.22. Multiple channel allocation and reuse of channels in the same time slot in P2PWRAN significantly increase the network capacity compared to standard IEEE 802.22 networks. One of...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Nov 2012

    A Polarization Enabled Cooperation Framework for Cognitive Radio Networking

    A novel polarization enabled two-phase cooperation framework for cognitive radio networking is proposed in this paper. By leveraging the degrees of freedom provided by orthogonally dual-polarized antennas, secondary users can relay the traffic of primary users and transmit their own in the same time slot without interference. To evaluate the...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Nov 2012

    Optimal Energy-Delay Tradeoff Policies in Cognitive Radio Networks

    Cognitive Radio (CR) has been considered as a promising technology to enhance spectrum efficiency via opportunistic transmission at link level. The authors consider Opportunistic Spectrum Access (OSA) mechanism that takes into account packet delay and energy consumption. They formulate the OSA problem as a Partially Observable Markov Decision Process (POMDP)...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Nov 2012

    Fair Channel Allocation and Access Design for Cognitive Ad Hoc Networks

    The authors investigate the fair channel assignment and access design problem for cognitive radio ad hoc network in this paper. In particular, they consider a scenario where ad hoc network nodes have hardware constraints which allow them to access at most one channel at any time. They investigate a fair...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Nov 2012

    Coordinated Optimization of Underlay Network Communication for Efficient Use of Spectrum

    Underlay communications has the potential to become a valuable tool for increasing the capacity of spectrum provided that the quality of communications is upheld. In this paper, the authors propose a method for underlay nodes to detect, and coordinate with, other underlay nodes to form a network on preoccupied spectrum....

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Nov 2012

    Joint Spectrum Sensing and Resource Allocation for Multi-band Cognitive Radio Systems with Heterogeneous Services

    In this paper, the authors study joint spectrum sensing and resource allocation for heterogeneous services in multi-band cognitive radio systems. Two types of services are considered: Delay-Sensitive (DS) services and Delay-Tolerant (DT) services. Considering the influence of the probabilities of miss detection and false alarm, the detection threshold, power and...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Nov 2012

    Exploiting Channel Correlation and PU Traffic Memory for Opportunistic Spectrum Scheduling

    The authors consider a cognitive radio network with multiple Primary Users (PUs) and one Secondary User (SU), where a spectrum server is utilized for scheduling the SU to transmit over one of the PU channels opportunistically. One practical yet challenging scenario is when both the PU occupancy and the channel...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Nov 2012

    Joint Multiuser Switched Diversity and Adaptive Modulation Schemes for Spectrum Sharing Systems

    In this paper, the authors develop multiuser access schemes for spectrum sharing systems whereby secondary users are allowed to share the spectrum with primary users under the condition that the interference observed at the primary receiver is below a predetermined threshold. In particular, they devise two schemes for selecting a...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Nov 2012

    Outage Analysis for Underlay relay-assisted Cognitive Networks

    Cooperative relay technology was recently introduced into cognitive radio networks in order to enhance network capacity, scalability, and reliability of end-to-end communication. In this paper, the authors investigate an underlay cognitive network where the quality of service of the secondary link is maintained by triggering an opportunistic regenerative relaying once...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Nov 2012

    A Novel Secondary User Assisted Relay Mechanism in Cognitive Radio Networks with Multiple Primary Users

    A relay-based mechanism is proposed in a multichannel cognitive radio network, while the multiple Primary Users (PUs) are considered in each channel. This mechanism guarantees that PUs achieve rates increment due to the assistance of the Secondary Users (SUs) in their transmission, while the SUs acquire reserved leasing timeslot to...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Nov 2012

    Pattern Classification Techniques for Cooperative Spectrum Sensing in Cognitive Radio Networks: SVM and W-KNN Approaches

    The authors consider novel Cooperative Spectrum Sensing (CSS) algorithms based on the pattern classification techniques for Cognitive Radio (CR) networks. In this regard, Support Vector Machine (SVM) and weighted K-Nearest-Neighbor (KNN) classification techniques are implemented for CSS. The received signal strength at the CR users are treated as features and...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Nov 2012

    A Cooperative DoA-based Algorithm for Localization of Multiple Primary-Users in Cognitive Radio Networks

    Knowledge about the location of licensed Primary Users (PU) could enable several key features in Cognitive Radio (CR) networks including improved spatio-temporal sensing, intelligent location-aware routing, as well as aiding spectrum policy enforcement. In this paper the authors discuss the problem of localizing multiple PUs based on Direction-of-Arrival (DoA) measurements....

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Nov 2012

    Traffic Generator using Perlin Noise

    Study of high speed networks such as optical next generation burst or packet switched networks require large amounts of synthetic traffic to feed simulators. Methods to generate self-similar long range dependent traffic already exist but they usually work by generating large blocks of traffic of fixed time duration. This limits...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Nov 2012

    Cooperative On-Demand Delivery for IPTV Networks

    In this paper, the authors investigate the use of cooperative transmission strategies to support timely and efficient delivery of on-demand content to end users. Within the proposed framework, a cooperative transmission strategy suggests that users who have access to the requested content cooperatively transmit to the targeted users to minimize...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Nov 2012

    Resource Management for Macrocell Users in Hybrid Access Femtocells

    The constant evolution of mobile-phone traffic demands for novel networking solutions especially focused on indoor environment. In this paper, the use of femtocells, i.e., cells with very limited coverage area, has been proposed. In this paper, a femtocell network with hybrid access control mode is considered. The activity profile of...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Nov 2012

    SDRE: Selective Data Redundancy Elimination for Resource Constrained Hosts

    Data Redundancy Elimination (DRE), also known as data de-duplication, reduces the data amount to be transferred or stored by identifying and eliminating both intra-object and inter-object duplicated data elements. It is one of the key content delivery acceleration techniques over Wide Area Networks (WANs) to reduce delivery latency and bandwidth...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Nov 2012

    Quantifying and Mitigating IGMP Filtering in Topology Discovery

    Recent developments in router level topology discovery have suggested the introduction of IGMP probing in addition to standard techniques such as traceroute and alias resolution. With a single IGMP probe, one can obtain all multicast interfaces and links of a multicast router. If such a probing is a promising approach,...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Feb 2011

    Live Streaming With Receiver-Based Peer-Division Multiplexing

    A number of commercial Peer-To-Peer (P2P) systems for live streaming have been introduced in recent years. The behavior of these popular systems has been extensively studied in several measurement papers. Due to the proprietary nature of these commercial systems, however, these studies have to rely on a "Black-box" approach, where...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Feb 2011

    Forward Correction and Fountain Codes in Delay-Tolerant Networks

    Delay-tolerant ad hoc networks leverage the mobility of relay nodes to compensate for lack of permanent connectivity and thus enable communication between nodes that are out of range of each other. To decrease delivery delay, the information to be delivered is replicated in the network. The authors' objective in this...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Feb 2011

    Cross-Layer Jamming Detection and Mitigation in Wireless Broadcast Networks

    Wireless communication systems are often susceptible to the jamming attack where adversaries attempt to overpower transmitted signals by injecting a high level of noise. Jamming is difficult to mitigate in broadcast networks because transmitting and receiving are inherently symmetric operations: a user that possesses the key to decode a transmission...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Nov 2011

    Reciprocal Spectrum Sharing Game and Mechanism in Cellular Systems With Cognitive Radio Users

    To fully exploit Cognitive Radio (CR) techniques as secondary transmissions in exiting Primary Systems (PSs), especially cellular systems, the authors propose a cooperative spectrum sharing mechanism where CR users serve as relay nodes to enhance PS's performance, and PS leases some portion of resources for CR users' networking services by...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Nov 2011

    Network Synchronization Among Femtocells

    To successfully deploy femtocells overlaying the Macrocell as a two-tier that had been shown greatly benefiting communications quality in various manners, it requires to mitigate cross-tier interference between the Macrocell and femtocells, as well as intra-tier interference among femtocells. For this purpose, solutions for interference mitigation have been proposed for...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Jan 2012

    Iterative Tracking the Minimum of Overall Energy Consumption in OFDMA Systems

    Although energy efficiency of communication systems has been studied for years, minimizing overall energy consumption of OFDMA downlink systems is still a challenge. In view of usual implementations, in this paper the energy consumption of control processor, specific circuit and analog front-end are jointly minimized, with algorithm complexity, resource scheduling,...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Jan 2012

    Exploring Terabit Wireless Potential of Wavelength Division Multiplexing

    Terabit wireless potential of Wavelength Division Multiplexing (WDM) is explored in this paper, through a novel detection algorithm over single-slit receiver. Different from current solutions that separates signals on different wavelengths by optical components (e.g. lens), the authors' solution is based on simpler architecture and signal processing. The receiving signal...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Jan 2012

    Energy Efficient OFDMA: Trade-Off Between Computation and Transmission Energy

    The authors study minimization of overall energy consumption of OFDMA systems, which are widely adopted in future wireless communications. Based on the existing resource allocation to minimize transmission energy, the computation energy increases due to the complexity of allocating algorithms. Since, high performance algorithms usually have high complexity, there exist...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Mar 2012

    Large Families of Asymptotically Optimal Two-Dimensional Optical Orthogonal Codes

    Nine new 2-D OOCs are presented here, all sharing the common feature of a code size that is much larger in relation to the number of time slots than those of constructions appearing previously in the literature. Each of these constructions is either optimal or asymptotically optimal with respect to...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Sep 2010

    From Opportunistic Networks to Opportunistic Computing

    Personal computing devices, such as smartphones and PDAs, are commonplace, bundle several wireless network interfaces, can support compute intensive tasks, and are equipped with powerful means to produce multimedia content. Thus, they provide the resources for what the authors envision as a human pervasive network: a network formed by user...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Jun 2011

    A Delay-Centric Dynamic Resource Allocation Algorithm for Wireless Communication Systems Based on HNN

    This paper proposes a Dynamic Resource Allocation (DRA) algorithm for packet data services in wireless communication systems based on Hopfield Neural Networks (HNN). The resource allocation algorithm assumes a delay-centric approach in that it maximizes resource utilization of the overall system while minimizing the packet delay. The real-time working capability...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Jun 2011

    User Bandwidth Usage - Driven HNN Neuron Excitation Method for Maximum Resource Utilization Within Packet - Switched Communication Networks

    Mobile and wireless systems beyond 3G are being designed under the user-centric paradigm. Dynamic Resource Allocation (DRA) is a topic on intensive research to address efficiently such paradigm. Hopfield Neural Networks (HNN) have proved useful in the past to solve this kind of complex optimization problems. Recently, various approaches have...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Jun 2011

    Analysis and Validation of a Shadowing Simulation Model Suited for Dynamic and Heterogeneous Wireless Networks

    Complete shadowing modelling is one of the key issues when performing system level simulation of wireless networks. So far, models have been defined considering fixed antenna heights and a cellular deployment of base stations over roofs. However in multi-hop networks, like vehicle-to-vehicle systems, mobile equipments can be in constant three-dimensional...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Jun 2011

    Mobile Terminal Session SIR Prediction Method Based on Clustering and Classification Algorithms

    In this paper, a novel method for mobile terminal session Signal to Interference Ratio (SIR) prediction is presented. The method is based on clustering and classification algorithms configuring a fully-automatic process, highly adaptable to the deployment scenario. It is focused on the prediction of the session SIR probability density function...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Jun 2011

    MAC Layer Performance of Different Channel Estimation Techniques in UTRAN LTE Downlink

    Long Term Evolution (LTE) is the new standard proposed by the 3GPP to evolve towards 4G. Evolved UTRAN (E-UTRAN) specifications are currently completed and research groups are studying the performance of the last Release 8. Nevertheless, these studies lack of a full modeling of the MAC layer because they either...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Jun 2011

    Complete Shadowing Modeling and Its Effect on System Level Performance Evaluation

    Computer simulations are a common procedure for assessing the performance of new algorithms. To conduct a valid and accurate study, the models employed in such simulators need to be carefully selected. Regarding shadowing modeling, one-dimensional models are fairly commonplace in the literature. While simple and with low computational costs, these...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Jun 2011

    Joint Dynamic Resource Allocation for Coupled Heterogeneous Wireless Networks Based on Hopfield Neural Networks

    This paper proposes an algorithm to solve the problem of Joint Dynamic Resource Allocation in heterogeneous wireless networks. The algorithm is based on Hopfield Neural Networks to achieve fast and suboptimal solutions. The generic formulation is particularized and evaluated in an HSDPA and 802.11e WLAN coupled networks. Some illustrative simulations...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Dec 2011

    QoS-Aware Load Balancing in 3GPP Long Term Evolution Multi-Cell Networks

    In this paper, the authors investigate load balancing problem in 3GPP Long Term Evolution (LTE) network. Since LTE network aims to serve heterogeneous users with different Quality of Service (QoS) requirements, the influence of load imbalance is quite different. For those users with minimum rate requirements, it may result in...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Dec 2011

    On the Diagonal Distribution of a Complex Wishart Matrix and Its Application to the Analysis of MIMO Systems

    The statistical properties of Wishart matrices have been extensively used to analyze the performance of Multiple-Input Multiple-Output (MIMO) systems. In particular, the Signal-to-Noise Ratio (SNR) output statistics of several MIMO systems depends on the diagonal distribution of a complex Wishart matrix. In this paper, the authors derive the joint density...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Apr 2010

    Outage Probability Analysis for Nakagami-q (Hoyt) Fading Channels Under Rayleigh Interference

    Exact closed-form expressions are obtained for the outage probability of Nakagami-q (Hoyt) fading channels under Co-Channel Interference (CCI). The scenario considered in this work assumes the joint presence of background white Gaussian noise and independent Rayleigh interferers with arbitrary powers. Outage probability is a key performance metric of wireless communication...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Nov 2011

    Minimum Rate Guaranteed Call Admission Control for Cumulative Rate Distribution Based Scheduling

    In this paper, the authors investigate Call Admission Control (CAC) for Cumulative rate distribution based Scheduling (CS) in wireless communication networks. They first analyze the Multiuser Diversity Gain (MDG) of CS, which is applicable to general channel conditions. Then, they propose the minimum rate guaranteed CS/ORR based CAC algorithm, COCAC,...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Jan 2012

    An Analysis of Requirements to Supporting Mobility in Body Area Networks

    Body Area Networks (BANs) form a strongly growing research field, motivated by increasing need for remote and improved patient healthcare solutions and driven by the development of the IEEE 802.15.6 standard. While most research focuses on single hop star topologies, more studies point towards multi-hop topologies as more preferable. Related...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Oct 2011

    An Analytical Model to Study the Impact of Time-Varying Cell Capacity in LTE Networks

    Contemporary wireless networks like Long Term Evolution (LTE) employ a technique called Adaptive Modulation and Coding (AMC) to enhance the throughput of the users in the system. Applying AMC, however, causes the total cell capacity to vary over time as sessions are started and stopped and users move around. The...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Sep 2012

    Nanoelectronic Solutions for Hardware Security

    Information security has emerged as an important system and application metric. Classical security solutions use algorithmic mechanisms that address a small subset of emerging security requirements, often at high energy and performance overhead. Further, emerging side channel and physical attacks can compromise classical security solutions. Hardware based security solutions overcome...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // May 2012

    An Empirical Phase-Noise Model for MEMS Oscillators Operating in Nonlinear Regime

    Non-linearity of a silicon resonator can lead to improved phase-noise performance in an oscillator when the phase shift of the sustaining amplifier forces the operating point to a steeper phase-frequency slope. As a result, phase modulation on the oscillator frequency is minimized because the resonator behaves as a high-order phase...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Oct 2012

    Metameric Modulation for Diffuse Visible Light Communications with Constant Ambient Lighting

    Advances in solid-state lighting are renewing interest in the adoption of the visible spectrum for optical wireless communications. Under the luminaire-as-transmitter model, wireless communication is achieved by modulating LED(s) that must simultaneously meet the illumination mission. Illumination requirements include maintaining energy efficiency, constant color and intensity control whereas communications requirements...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Aug 2011

    Modeling and Designing of a New Indoor Free Space Visible Light Communication System

    Recent developments in solid-state Light-Emitting Diode (LED) materials and devices is driving a resurgence into the use of Free-Space Optics (FSO) for wireless broadband communication. This technology uses the visible spectrum provided by "White" LEDs that are becoming ubiquitous in lighting and has some desirable properties competitive with existing Radio...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // May 2010

    Directional Communication System for Short-Range Vehicular Communications

    Improving safety in vehicles is achieved today by improving their ability to perceive and react to threats in the environment. Much effort is directed towards increasing the safety envelope around each vehicle with the introduction of increasingly sophisticated sensor technology (e.g., ultrasound, video, thermal imaging, and LIDAR). This envelope can...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Nov 2010

    Spotlighting for Visible Light Communications and Illumination

    The trend toward solid state lighting with white LEDs has motivated much research for using these devices to provide wireless broadband data communications. Much work in this area has attempted to fit VLC into currently dominant indoor lighting modes. In this paper the authors explore spotlighting, which is appropriate lighting...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Oct 2012

    LAT Indoor MIMO-VLC

    Visible Light Communications (VLC) is an innovative technology that uses the visible spectrum for high-speed data communications. In this paper the authors investigate the use of MIMO in the design of luminaires supporting VLC and, specifically, in enabling localization and high data rate services. Localization and transmission appear as two...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Nov 2011

    Space Shift Keying (SSK) MIMO with Practical Channel Estimates

    In this paper, the authors study the performance of space modulation for Multiple-Input-Multiple-Output (MIMO) wireless systems with imperfect channel knowledge at the receiver. They focus their attention on two transmission technologies, which are the building blocks of space modulation: Space Shift Keying (SSK) modulation; and Time-Orthogonal - Signal-Design (TOSD -)...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Jan 2012

    Bit Error Probability of Spatial Modulation (SM) MIMO Over Generalized Fading Channels

    In this paper, the authors study the performance of Spatial Modulation (SM) Multiple-Input - Multiple-Output (MIMO) wireless systems over generic fading channels. More precisely, a comprehensive analytical framework to compute the Average Bit Error Probability (ABEP) is introduced, which can be used for any MIMO setups, for arbitrary correlated fading...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Apr 2012

    Clipping Noise in OFDM-Based Optical Wireless Communication Systems

    In this paper, the impact of clipping noise on Optical Wireless Communication (OWC) systems employing Orthogonal Frequency Division Multiplexing (OFDM) is investigated. The two existing Optical OFDM (O-OFDM) transmission schemes, Asymmetrically Clipped Optical OFDM (ACO-OFDM) and Direct Current-biased Optical OFDM (DCO-OFDM), are studied. Time domain signal clipping generally results from...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Nov 2012

    Usage Behavior of a Large-Scale Scientific Archive

    Archival storage systems for scientific data have been growing in both size and relevance over the past two decades, yet researchers and system designers alike must rely on limited and obsolete knowledge to guide archival management and design. To address this issue, the authors analyzed three years of file-level activities...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Apr 2011

    Object-Based SCM: An Efficient Interface for Storage Class Memories

    Storage Class Memory (SCM) has become increasingly popular in enterprise systems as well as embedded and mobile systems. However, replacing hard drives with SCMs in current storage systems often forces either major changes in file systems or suboptimal performance, because the current block-based interface does not deliver enough information to...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // May 2009

    A Single-Symbol-Decodable Space-Time Block Code with Full Rate and Low Peak-to-Average Power Ratio

    Three desirable properties of a four-antenna space-time block code are full rate, full diversity, and single-symbol decodability. Previously reported space-time codes that achieve all three properties do so at the expense of the Peak-to-Average Power Ratio (PAPR). A fourth desirable property of a space-time block code is that its PAPR...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Feb 2009

    On the Approximation of the Generalized-K PDF by a Gamma PDF Using the Moment Matching Method

    Using the Nakagami Probability Density Function (PDF) to model multipath fading and the Gamma PDF to model shadowing, in a wireless channel, has led to a closed-form expression for the composite fading PDF, known as the generalized-K PDF (also called Gamma-Gamma PDF). However, further derivations have shown that the Cumulative...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Feb 2009

    Analysis of Carrier Sensing's Influence on the Performance of Routing Protocols in Multi-Hop, Multi-Rate Wireless Networks

    Carrier sensing has been used as an effective way to reduce collisions and exploit spatial reuse in wireless networks. Previous research has attempted to tune the carrier sensing range to maximize the network throughput. However, the impact of carrier sensing threshold on the probability of successful transmission has been ignored....

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Feb 2009

    Distributed Interference-Aware Scheduling Schemes for High-Density WLAN

    The increasing density of WLAN devices induces severe inter-cell interference problem in now-a-days WLAN system. The traditional Distributed Coordination Function (DCF) mechanism in IEEE 802.11 protocol was designed for the avoidance of intra-cell collision, but the inter-cell interference cannot be alleviated by merely increasing the backoff time. Multi-cell scheduling mechanism...

    Provided By Institute of Electrical and Electronics Engineers

  • White Papers // Feb 2009

    Improved Beamforming for Radio Links with Multi-Level Linearly Modulated Signals

    Multiple constellations have been proposed recently as a way of improving the system performance when used in conjunction with Orthogonal Transmit Diversity (OTD) for high level linear modulation schemes. This paper considers the use of multiple constellations in Multiple Input Multiple Output (MIMO) antenna systems. The premise is that the...

    Provided By Institute of Electrical and Electronics Engineers