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# IET Communications

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Displaying Results 1 - 12 of 12
• ### Performance analysis of signal-to-interferenceplus- noise ratio-based selection diversity over correlated rayleigh fading channels

Publication Year: 2011, Page(s):127 - 134
| | PDF (264 KB)

In wireless communications systems, desired signal can be exposed to fading, cochannel interference (CCI) and noise. Diversity combining, such as space diversity, is a well-known method that can be used to alleviate the effects of these degradations. L-branch selection combining (SC) receiver which uses signal-to-interference-plus-noise ratio (SINR) power algorithm over correlated Rayleigh ... View full abstract»

• ### Performance of interference-limited dual-hop non-regenerative relays over rayleigh fading channels

Publication Year: 2011, Page(s):135 - 140
Cited by:  Papers (12)
| | PDF (359 KB)

This paper studies the performance of a dual-hop non-regenerative relay fading channel in an interference-limited environment. The relay and destination nodes are corrupted by co-channel interference. New closed-form expressions for the probability density function and cumulative distribution function of the output signal-to-interference ratio are derived. Analytical expressions for the outage pro... View full abstract»

• ### Efficient soft decoding of reed-solomon codes based on sphere decoding

Publication Year: 2011, Page(s):141 - 153
Cited by:  Papers (2)
| | PDF (990 KB)

A novel soft-decision decoding method motivated by the idea of sphere decoding is proposed for Reed-Solomon (RS) codes. Sphere decoding reduces the complexity of finding the closest lattice point to a given point by confining the search to points that fall inside a sphere around the given point. In the authors- proposed scheme, in order to reduce the search even further, the search effort is conce... View full abstract»

• ### Implementation of low-complexity companding technique for efficient peak-toaverage power ratio reduction in orthogonal frequency division multiplexing systems

Publication Year: 2011, Page(s):154 - 162
Cited by:  Papers (2)
| | PDF (679 KB)

Orthogonal frequency division multiplexing (OFDM) system has become an extremely popular wireless communication system in recent years. However, since the OFDM system is limited by a high peak-to-average power ratio (PAPR), companding techniques are often used to reduce PAPR. A uniformly distributed non-linear companding scheme offers efficient PAPR reduction with a low bit error rate (BER). Howev... View full abstract»

• ### Using two global positioning system satellites to improve wireless fidelity positioning accuracy in urban canyons

Publication Year: 2011, Page(s):163 - 171
Cited by:  Papers (4)
| | PDF (757 KB)

It is well known that a global positioning system (GPS) receiver needs to see at least four satellites to provide a three-dimensional fix solution. But in difficult environments such as an urban canyon, the number of visible satellites is often not enough. Wireless fidelity (WiFi) signals have been utilised for positioning mainly based on the fingerprinting technology. However, the accuracy of... View full abstract»

• ### Agent-driven backbone ring-based reliable multicast routing in mobile ad hoc networks

Publication Year: 2011, Page(s):172 - 189
Cited by:  Papers (2)
| | PDF (909 KB)

Routing in mobile ad hoc networks (MANETs) for groups should aim at providing reliable and robust multicast routes to the group members against link failures, node failures and mobility conditions. The authors propose an agent-based multicast routing scheme in MANET that builds a backbone in the form of a reliable ring and finds multicast routes. The authors use the convex hull algorithm to... View full abstract»

• ### Stable throughput and delay performance in cognitive cooperative systems

Publication Year: 2011, Page(s):190 - 198
Cited by:  Papers (6)
| | PDF (583 KB)

The cognitive cooperative system with coexisting scenario of multiple primary users and one secondary capable of relaying is considered in this study. The primary users transmit packets in orthogonal subchannels. According to the cognitive principle, the secondary activity cannot interfere with the primary performance. Therefore in this study, the secondary user makes use of the spectrum when sens... View full abstract»

• ### Kalman smoothing-based adaptive frequencydomain channel estimation for uplink multiple-input multiple-output orthogonal frequency division multiple access systems

Publication Year: 2011, Page(s):199 - 208
| | PDF (676 KB)

This study investigates Kalman smoothing (KS)-based frequency-domain channel estimation for uplink multiple-input multiple-output (MIMO) orthogonal frequency division multiple access (OFDMA) systems with time-varying channels. The proposed KS channel estimation scheme significantly outperforms the recursive least squares (RLS) channel estimation in the high signal-to-noise ratio (SNR) range, becau... View full abstract»

• ### Improved superimposed training-based channel estimation method for closed-loop multiple input multiple output orthogonal frequency division multiplexing systems

Publication Year: 2011, Page(s):209 - 221
Cited by:  Papers (1)
| | PDF (706 KB)

This study pertains to the use of superimposed training (ST) in closed-loop multiple input multiple output (MIMO) orthogonal frequency division multiplexing (OFDM) systems. A novel method consisting of a technique to refine the channel estimate at the transmitter in an ST-based closed-loop MIMO-OFDM system is proposed. The estimate is refined at the transmitter by making use of the previous data t... View full abstract»

• ### Efficient construction of irregular codes with midterm block length and near-shannon performance

Publication Year: 2011, Page(s):222 - 230
| | PDF (862 KB)

In this study, the authors propose a new method for constructing irregular low-density parity-check codes (LDPC codes) with midterm or short block lengths. It is a Monte-Carlo simulation-based optimisation procedure called downhill simplex which uses progressive edge growth method for Tanner graph construction in cost function evaluations. It outperforms the density evolution (DE) method in both e... View full abstract»

• ### Design and performance analysis of non-data-aided carrier phase estimators for amplitude and phase shift keying signals

Publication Year: 2011, Page(s):231 - 239
Cited by:  Papers (2)
| | PDF (508 KB)

This study studies the feedforward (FF) non-data-aided (NDA) carrier phase estimation of the amplitude and phase shift keying (APSK) signals. The true Cramer-Rao bounds (CRBs) for NDA phase estimation of APSK signals are derived and evaluated numerically using Gauss-Hermite quadrature. The jitter variance of the FF Viterbi-Viterbi (V&V) algorithm is analysed assuming the absence of data patter... View full abstract»

• ### Green modulations in energy-constrained wireless sensor networks

Publication Year: 2011, Page(s):240 - 251
Cited by:  Papers (12)
| | PDF (511 KB)

Owing to the unique characteristics of sensor devices, finding the energy-efficient modulation with a low-complexity implementation (refereed to as green modulation) poses significant challenges in the physical layer design of wireless sensor networks (WSNs). Towards this goal, the authors present an in-depth analysis on the energy efficiency of various modulation schemes using realistic models in... View full abstract»

## Aims & Scope

IET Communications covers the theory and practice of systems, networks and applications involving line, mobile radio, satellite and optical technologies for telecommunications, and Internet and multimedia communications.

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