# IEEE Communications Letters

## Filter Results

Displaying Results 1 - 25 of 51

Publication Year: 2015, Page(s):C1 - 504
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• ### IEEE Communications Letters publication information

Publication Year: 2015, Page(s): C2
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• ### Efficient Decoding of Short Length Linear Cyclic Codes

Publication Year: 2015, Page(s):505 - 508
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Iterative soft decision decoding of linear block codes is a practical necessity when working with even modest block lengths. A number of algorithms have been proposed in the literature which use the permutation group of a code and the belief propagation (BP) algorithm for decoding. A novel soft-input, soft-output algorithm is presented that can be used for efficiently decoding of linear cyclic cod... View full abstract»

• ### A Distributed LT Code Design for Multiple-Access Relay Networks Subject to Erasures

Publication Year: 2015, Page(s):509 - 512
Cited by:  Papers (1)
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This letter proposes a new distributed Luby transform (LT) code which is particularly suitable for the multiple-access relay network with erasure channels. We analyze the asymptotic performance of our distributed coding scheme by virtue of AND-OR tree analysis and present the simulation results of finite length comparing with existing methodologies. The proposed coding scheme is shown to be superi... View full abstract»

• ### Variable-Length Feedback Codes Under a Strict Delay Constraint

Publication Year: 2015, Page(s):513 - 516
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We study variable-length feedback (VLF) codes under a strict delay constraint to maximize their average transmission rate (ATR) in a discrete memoryless channel (DMC) while considering periodic decoding attempts. We first derive a lower bound on the maximum achievable ATR, and confirm that the VLF code can outperform non-feedback codes with a larger delay constraint. We show that for a given decod... View full abstract»

• ### A Two-Stage Decoding Algorithm to Lower the Error-Floors for LDPC Codes

Publication Year: 2015, Page(s):517 - 520
Cited by:  Papers (4)
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A two-stage decoding algorithm to lower the error-floor for low-density parity-check (LDPC) codes is presented. An efficient stopping criterion is proposed to avoid unnecessary iterations in the first stage. If the stopping criterion is reached, the first stage decoding will be terminated and the second stage decoding will be started, where the unsuccessfully decoded words are re-decoded by manipu... View full abstract»

• ### Recoverability of Variable Nodes in Periodically Punctured LDPC Convolutional Codes

Publication Year: 2015, Page(s):521 - 524
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The concept of transformed codes is introduced to algebraically evaluate the recoverability of punctured nodes for periodically punctured low-density parity-check convolutional codes (LDPC-CCs) by a simple matrix-based approach. The proposed very efficient algorithm allows to identify and exclude those candidate puncturing patterns in a computer search that contain unrecoverable nodes that would l... View full abstract»

• ### Full-Duplex Relay for Enhancing Physical Layer Security in Multi-Hop Relaying Systems

Publication Year: 2015, Page(s):525 - 528
Cited by:  Papers (22)
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In this letter, we consider secure communications in multi-hop relaying systems, where full-duplex relays (FDRs) operate to enhance wireless physical layer security. Each FDR is designed to transmit jamming signals to the eavesdropper when it receives information signals from the previous adjacent node. The achievable secrecy rate with the proposed decode-and-forward (DF) FDRs are analyzed with a ... View full abstract»

• ### Equivalent Nonlinearities for Studying Nonlinear Effects on Sampled OFDM Signals

Publication Year: 2015, Page(s):529 - 532
Cited by:  Papers (2)
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In this work we consider nonlinear effects on sampled orthogonal frequency division multiplexing (OFDM) signals and we present a method for obtaining a polynomial function with small degree that can be used to substitute severe nonlinear characteristics (possibly non-differentiable, as clipping functions), since it leads to signals with essentially the same spectral characteristics. This equivalen... View full abstract»

• ### On the Capacity of Slotted Aloha With Ancillary Channels

Publication Year: 2015, Page(s):533 - 536
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In this letter, we focus on a legacy system operated with slotted-Aloha and complemented by a redundancy channel where nodes transmit replicas of their packets. The number of replicas follows a probability distribution, and successive interference cancelation is applied across channels. Leaning on the theory of codes on graphs and algebraic tools, we prove that the system can provide arbitrarily s... View full abstract»

• ### Modeling Heterogeneous Virtual Machines on IaaS Data Centers

Publication Year: 2015, Page(s):537 - 540
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This letter considers the IaaS data center where tenant tasks are different in terms of the number of requested physical cores, leading to heterogeneous virtual machines (VMs). We develop a novel analytical model to evaluate the performance of heterogeneous VMs on the same physical machine by applying the Continuous Time Markov Chain. View full abstract»

• ### GreCo: An Energy Aware Controller Association Algorithm for Software Defined Networks

Publication Year: 2015, Page(s):541 - 544
Cited by:  Papers (8)
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Software Defined Networks (SDNs) separate the control and data planes of devices to expedite the deployment, configuration and evolution of networks. In this respect, controllers play a key role. In particular, they control the behavior of switches and must do so quickly. This, however, may be at odds with the goal of reducing the energy consumption of a SDN because powering down links may cause c... View full abstract»

• ### LRURC: A Low Complexity and Approximate Fair Active Queue Management Algorithm for Choking Non-Adaptive Flows

Publication Year: 2015, Page(s):545 - 548
Cited by:  Papers (1)
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Active Queue Management is an effective way to improve the TCP's performance. However, due to the existence of non-adaptive flows, most previous schemes cannot achieve efficiency, fairness, and easy-to-deploy simultaneously. In this paper, a novel scheme, named LRURC, is proposed to improve the fairness among different flows and reduce the flow completion time when the high-bandwidth non-adaptive ... View full abstract»

• ### Analysis of Modulation Order to Guarantee Real-Time Service Throughputs in OFDMA-PON

Publication Year: 2015, Page(s):549 - 552
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In an orthogonal frequency-division multiple access passive optical network (OFDMA-PON), each optical network unit (ONU) chooses a modulation format based on the signal-to-noise ratio (SNR) at its receiver. An ONU with a high SNR can use a high-order modulation format to increase its transmission efficiency. When upstream resources are fully utilized, this increases an aggregated upstream throughp... View full abstract»

• ### Serial Relaying Over Gamma-Gamma MIMO FSO Links: Diversity Order and Aperture Allocation

Publication Year: 2015, Page(s):553 - 556
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Serial relaying is analyzed in the context where the Free-Space Optical (FSO) communicating nodes are equipped with multiple apertures. We derive asymptotic expressions for the outage probability over the gamma-gamma fading channel and we evaluate the diversity orders that can be achieved by combining the multi-hop and multi-aperture techniques. A recursive algorithm that optimally allocates the a... View full abstract»

• ### Simultaneous Optical Phase and Intensity Modulation Transmits Independent Signals in Radio Over Fiber Communication

Publication Year: 2015, Page(s):557 - 560
Cited by:  Papers (2)
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We propose and mathematically characterize a novel Radio Over Fiber (ROF) architecture, which uses a single MZM for simultaneously modulating the intensity and phase of an optical carrier with either two different RF signals or a RF signal and a baseband signal. The detection of these two independent signals is conceived along with possible applications of the proposed architecture. The operation ... View full abstract»

• ### A Double-Layer VLC System With Low-Complexity ML Detection and Binary Constellation Designs

Publication Year: 2015, Page(s):561 - 564
Cited by:  Papers (2)
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We consider a double-layer visible light communication system where transmitted data is split into two layers with different priorities and variant transmission rates. High-priority data is assigned to the upper layer with low transmission rate, while low-priority data is assigned to the lower layer with higher transmission rate. For this scenario, we develop a low-complexity maximum likelihood de... View full abstract»

• ### Flexible Bandwidth Allocation in Filterless Optical Networks

Publication Year: 2015, Page(s):565 - 568
Cited by:  Papers (3)
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We introduce the new concept of an elastic filterless optical network and propose an efficient heuristic algorithm for solving the static routing and spectrum assignment problem. Our simulation results obtained for different network topologies under multi-period traffic show increasing bandwidth savings with the growth of traffic load compared to a fixed-grid scenario. We also show the benefits of... View full abstract»

• ### Impact of Limiting Hop Count on the Lifetime of Wireless Sensor Networks

Publication Year: 2015, Page(s):569 - 572
Cited by:  Papers (4)
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In this study, we present a novel family of mixed integer programming (MIP) models to analyze the effects of limiting hop count on Wireless Sensor Network (WSN) lifetime. We performed analysis to uncover the trade-off between minimizing the number of hops and maximizing the network lifetime by exploring the parameter space through numerical evaluations of the optimization models. Our results revea... View full abstract»

• ### On the Output Rate of Overloaded Link Schedulers

Publication Year: 2015, Page(s):573 - 576
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We derive and compare properties of the output rates at overloaded links for three types of link scheduling algorithms: First-in-First-Out (FIFO), Static-Priority (SP), and Earliest-Deadline-First (EDF). Under most general assumptions, i.e., each traffic flow has a long-term average rate, we show that the output rates of flows at overloaded FIFO and EDF links are proportional to their input rates.... View full abstract»

• ### Macroscopic Malware Propagation Dynamics for Complex Networks With Churn

Publication Year: 2015, Page(s):577 - 580
Cited by:  Papers (3)
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In this letter, a queueing-based approach for modeling malware propagation in complex networks with churn (dynamic node variation) is introduced. The proposed methodology captures the dynamics of SIS-type malware, especially in time-varying networks, where nodes enter and leave due to their limited energy reserves, or as the outcome of malware attacks. We demonstrate the developed model in various... View full abstract»

• ### Advanced Stealth Man-in-The-Middle Attack in WPA2 Encrypted Wi-Fi Networks

Publication Year: 2015, Page(s):581 - 584
Cited by:  Papers (3)
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The Hole 196 vulnerability allows malicious insiders to inject spoofed broadcast/multicast frames encrypted with group transient key in the Wi-Fi Protected Access II (WPA2) enabled Wi-Fi networks. In this letter, we propose a novel insider attack-Advanced Stealth Man-in-The-Middle (ASMiTM) that combines Stealth Man-in-The-Middle (SMiTM) and Wireless Denial of Service (WDoS) attacks, both of which ... View full abstract»

• ### The Autocorrelation Magnitude of Balanced Binary Sequence Pairs of Prime Period $N\equiv 1(\bmod\ 4)$ With Optimal Cross-Correlation

Publication Year: 2015, Page(s):585 - 588
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In this paper, for balanced binary sequence pairs (BBSPs for short) of period N ≡ 1(mod, 4), the optimality of their cross-correlation is determined. Next, a lower bound on the maximal out-of-phase autocorrelation magnitude is established for BBSPs of period N ≡ 1(mod, 4) with optimal cross-correlation. Furthermore, BBSPs with optimal cross-correlation whose maximal out-of-phase auto... View full abstract»

• ### Optimal Precoder Design Maximizing the Worst-Case Average Received SNR for Massive Distributed MIMO Systems

Publication Year: 2015, Page(s):589 - 592
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In this letter, we consider a distributed multiple-input multiple-output (D-MIMO) system, where the channel is flat fading and may be correlated, and experiences both small and large-scale fading. We assume that the full knowledge of channel state information (CSI) is available at the receiver and only the first-and second-order statistics of the channel are available at the transmitter. For such ... View full abstract»

• ### The Cognitive Interference Channel With a Causal Relay in Very Strong Interference

Publication Year: 2015, Page(s):593 - 596
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We study the cognitive interference channel where an additional node (a relay) is present. In our model the relay's operation is causal rather than strictly causal, i.e., the relay's transmit symbol depends not only on its past but also on its current received symbol. We derive outer bounds for the discrete and Gaussian cases in very strong interference. A scheme for achievability based on instant... View full abstract»

## Aims & Scope

IEEE Communications Letters publishes letters on the frontiers of research within the field of interest of the IEEE Communications Society in a timely manner.

Full Aims & Scope

Editor-in-Chief
Octavia Dobre