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# IEEE Communications Letters

## Filter Results

Displaying Results 1 - 25 of 51

Publication Year: 2015, Page(s):C1 - 892
| PDF (108 KB)
• ### IEEE Communications Letters publication information

Publication Year: 2015, Page(s): C2
| PDF (136 KB)
• ### A New Cross-Level Decoding Scheme for LT Codes

Publication Year: 2015, Page(s):893 - 896
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In this letter, we propose a new cross-level decoding method for LT codes, where the results of packet-level decoding are fed back to bit-level decoding to improve the overall decoding performance. Another advantage of our method is that it keeps the original LT decoder structure and does not require extra real field computation. We provide the revised And-Or Tree analysis for the proposed method ... View full abstract»

• ### Low-Complexity and Piecewise Systematic Encoding of Non-Full-Rank QC-LDPC Codes

Publication Year: 2015, Page(s):897 - 900
Cited by:  Papers (1)
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In this letter, we present a low-complexity encoding method for quasi-cyclic (QC) low-density parity-check (LDPC) codes in the case of non-full-rank parity-check matrices. Gaussian elimination can achieve systematic encoding, but it is usually too complex to implement. For QC-LDPC codes, efficient encoding methods have been presented by using shift-registers, but the encoded codewords are not syst... View full abstract»

• ### Heterogeneity-Aware Codes With Uncoded Repair for Distributed Storage Systems

Publication Year: 2015, Page(s):901 - 904
Cited by:  Papers (5)
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In practical large-scale distributed storage systems, node failures are unavoidable. It is therefore desirable to quickly recreate the failed nodes in order to maintain the system integrity. In this letter, we consider a family of erasure codes that provide uncoded repair, where the failed node is regenerated by transfer of data without extra arithmetic operations. We introduce flexible fractional... View full abstract»

• ### Multiple-Votes Parallel Symbol-Flipping Decoding Algorithm for Non-Binary LDPC Codes

Publication Year: 2015, Page(s):905 - 908
Cited by:  Papers (3)
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A novel decoding algorithm for non-binary low density parity check (NB-LDPC) codes is proposed. The algorithm builds on the recently designed parallel symbol-flipping decoding (PSFD) algorithm and combines a technique of error estimation and a method of multiple voting levels from each unsatisfied check-sum to the corresponding variable nodes. Simulations results, performed on a number of NB-LDPC ... View full abstract»

• ### Reduced-Complexity Linear Programming Decoding Based on ADMM for LDPC Codes

Publication Year: 2015, Page(s):909 - 912
Cited by:  Papers (11)
| | PDF (966 KB) | HTML

The Euclidean projection onto check polytopes is the most time-consuming operation in the linear programming (LP) decoding based on alternating direction method of multipliers (ADMM) for low-density parity-check (LDPC) codes. In this letter, instead of reducing the complexity of Euclidean projection itself, we propose a new method to reduce the decoding complexity of ADMM-based LP decoder by decre... View full abstract»

• ### Improved ADMM Penalized Decoder for Irregular Low-Density Parity-Check Codes

Publication Year: 2015, Page(s):913 - 916
Cited by:  Papers (11)
| | PDF (834 KB) | HTML

Based on linear programming (LP) decoding with alternating direction method of multipliers (ADMM), Liu et al. proposed an ADMM penalized decoder for low-density parity-check (LDPC) codes that can improve the error rate performance at low signal-to-noise ratios. In this letter, we propose a new ADMM penalized decoder to improve the error rate performance further for irregular LDPC codes. The propos... View full abstract»

• ### Cluster Error Correction for Real-Time Channels by Unbound Rotation of Two-Dimensional Parity-Check Codes

Publication Year: 2015, Page(s):917 - 920
Cited by:  Papers (1)
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Circuit-level real-time channels like through-silicon vias generally admit only several levels of logic gates for decoding within a clock cycle. From our study two-dimensional parity check has the greatest potential for on-line monitoring and correcting. The bounded rotation scheme for cyclic decoding is first applied in real-time channels with four times of relative correctable cluster size. An u... View full abstract»

• ### Bitwise Log-Likelihood Ratios for Quadrature Amplitude Modulations

Publication Year: 2015, Page(s):921 - 924
Cited by:  Papers (4)
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For an increase in spectral efficiency and improvement of error performance, a high-order modulation and an advanced channel coding scheme are jointly used for many digital communication systems. In this paper, a new and simple method for calculating bitwise log-likelihood ratios which are required for soft decision decoding is proposed for M-ary quadrature amplitude modulations. The mean square e... View full abstract»

• ### Low-Complexity Power Allocation for Energy Efficiency Maximization in DAS

Publication Year: 2015, Page(s):925 - 928
Cited by:  Papers (6)
| | PDF (440 KB) | HTML

Different from traditional power allocation schemes in distributed antenna systems, a novel power allocation algorithm aiming at maximizing energy efficiency (EE) with low-complexity is presented in this letter. The optimization process is divided into two steps, the first step is to find the optimal number of antennas corresponding to any fixed total dynamic power constraints. The second step is ... View full abstract»

• ### An Improved Particle Smoother for Blind Equalization in Time-Varying MIMO Channels

Publication Year: 2015, Page(s):929 - 932
| | PDF (260 KB) | HTML

An improved fixed-lag particle smoother in the mixture Kalman filter (MKF) framework is developed for the blind equalization in time-varying multiple-input multiple-output (MIMO) channels. The improved particle smoother utilizes the uniform proposal distribution (PD) and the optimal resampling to generate particles. Compared to the particle smoother with the posterior PD, the improved particle smo... View full abstract»

• ### IPv6-Based Vehicular Cloud Networking

Publication Year: 2015, Page(s):933 - 936
Cited by:  Papers (2)
| | PDF (685 KB) | HTML

In a vehicular cloud network, content-centric approaches are usually employed to seek contents. In the content-centric approaches, data attributes are used for routing instead of a specific address such as an IP address; i.e, data attributes are broadcasted in a vehicular cloud network to seek target contents. This flooding inevitably increases the cost of contents acquisition. To reduce the cost ... View full abstract»

• ### Further Complexity Reduction for Antenna Selection in Spatial Modulation Systems

Publication Year: 2015, Page(s):937 - 940
Cited by:  Papers (9)
| | PDF (572 KB) | HTML

In this letter, the transmit antenna selection in the spatial modulation system is studied. First, the computational complexity of the transmit antenna selection algorithm previously proposed elsewhere is reduced through an alternative computation of the singular value. Second, the minimum distance ascent (MDA) search is proposed to reduce the search complexity, where the initial antenna subset is... View full abstract»

• ### An Algorithm for the Evaluation of the Throughput of a TCP NewReno Bulk Data Flow

Publication Year: 2015, Page(s):941 - 944
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This letter presents a simple and accurate algorithm to evaluate the steady-state throughput of a TCP NewReno bulk data flow as a function of the round-trip time, the retransmission timer value, and the loss behavior of the network. This work proposes a new method for evaluating the throughput of a TCP NewReno connection over any network whose end-to-end packetloss process can be described by an a... View full abstract»

• ### A Secure Multiple-Access Scheme for Rechargeable Wireless Sensors in the Presence of an Eavesdropper

Publication Year: 2015, Page(s):945 - 948
Cited by:  Papers (1)
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We propose a simple yet efficient scheme for a set of energy-harvesting sensors to establish secure communication with a common destination (a master node). An eavesdropper attempts to decode the data sent from the sensors to their common destination. We assume a single modulation scheme that can be implemented efficiently for energy-limited applications. We design a multiple-access scheme for the... View full abstract»

• ### Anti-Jamming Transmission Stackelberg Game With Observation Errors

Publication Year: 2015, Page(s):949 - 952
Cited by:  Papers (11)
| | PDF (293 KB) | HTML

As smart jammers that can analyze the ongoing radio transmission with flexible and powerful control on jamming signals throw serious threats on cognitive radio networks, game theory provides a powerful approach to study the interactions between smart jammers and secondary users (SUs). In this work, the power control strategy of an SU against a smart jammer under power constraints is formulated as ... View full abstract»

• ### Thresholded Smoothed $\ell_0$ Norm for Accelerated Sparse Recovery

Publication Year: 2015, Page(s):953 - 956
| | PDF (535 KB) | HTML

Smoothed ℓ0 norm (SL0) is a fast and complex domain extendible sparse recovery algorithm which is suitable for many practical real-time applications. In this letter, we propose an improved algorithm termed “Thresholded Smoothed ℓ0 Norm (T-SL0)” for accelerating the iterative process of SL0. T-SL0 introduces an iterative efficiency indicator and com... View full abstract»

• ### Improving Routing Table Lookup in Software Routers

Publication Year: 2015, Page(s):957 - 960
Cited by:  Papers (2)
| | PDF (245 KB) | HTML

For the speed-up in the routing table lookup in software routers, we introduce a new data structure called, sTable that achieves space efficiency while causing low processing overhead without hardware parallelism. Using a hash table-like approach, sTable stores only next hop information to handle most packets within the on-chip fast memory while causing some accesses to the off-chip slow memory to... View full abstract»

• ### Adaptive GNSS Carrier Tracking Under Ionospheric Scintillation: Estimation vs. Mitigation

Publication Year: 2015, Page(s):961 - 964
Cited by:  Papers (5)
| | PDF (970 KB) | HTML

This letter deals with carrier synchronization in Global Navigation Satellite Systems. The main goals are to design robust methods and to obtain accurate phase estimates under ionospheric scintillation conditions, being of paramount importance in safety critical applications and advanced receivers. Within this framework, the estimation versus mitigation paradigm is discussed together with a new ad... View full abstract»

• ### A User-Side Energy-Saving Video Streaming Scheme for LTE Devices

Publication Year: 2015, Page(s):965 - 968
Cited by:  Papers (2)
| | PDF (549 KB) | HTML

Today, most streaming services rely on HyperText Transfer Protocol (HTTP) to deliver the contents to users, and mobile users are increasingly choosing Long Term Evolution (LTE) as the wireless access mode. In this letter, we propose a user-side scheme that takes LTE modem operation into account in video streaming over HTTP, leading to as much battery saving gain as 40% without Discontinuous Recept... View full abstract»

• ### A Distance-Dependent Free-Space Optical Cooperative Communication System

Publication Year: 2015, Page(s):969 - 972
Cited by:  Papers (4)
| | PDF (265 KB) | HTML

A distance-dependent cooperative scheme is proposed for free-space optical communications with a single-relay-assisted scenario. The new scheme exploits a fact that the diversity order of a free-space optical channel is related to the link distance. It is shown that, both analytically and numerically, the frame error rate of the new scheme can provide higher diversity order than a benchmark adapti... View full abstract»

• ### Multi-Dimensional Bid Greedy Auction Mechanism for Bandwidth Allocation

Publication Year: 2015, Page(s):973 - 976
| | PDF (296 KB) | HTML

Since current bandwidth mechanisms need communicating general functions or long convergence phase, they are not feasible in practice. In this letter, an efficient bandwidth allocation mechanism is proposed, which called Multi-dimensional Bid Greedy auction mechanism. It presents the advantage that the Multi-dimensional bid is submitted once only, saving a lot of signalization overhead. We formulat... View full abstract»

• ### Impact of Channel Switching in Energy Constrained Cognitive Radio Networks

Publication Year: 2015, Page(s):977 - 980
Cited by:  Papers (4)
| | PDF (659 KB) | HTML

In this letter, we investigate the energy efficiency of multichannel spectrum access in cognitive radio networks. We consider two channel access schemes. In one case, a secondary user (SU) is assigned multiple channels and the channels are switched whenever a primary user (PU) returns. In the other, the SU operates on a single channel without switching to other channels. We develop an analytic fra... View full abstract»

• ### How Many Antennas Should Be Activated in Keyhole Channels Under a Holistic Power Model

Publication Year: 2015, Page(s):981 - 984
| | PDF (316 KB) | HTML

In this letter, we investigate the problem of how many transmit or receive antennas should be activated in keyhole channels with the consideration of a holistic power model. In conventional works where the circuit power is ignored, the system performance in terms of both ergodic capacity and outage probability improves with the increase of active antennas. However, when a holistic power model whic... 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