# IET Communications

## Filter Results

Displaying Results 1 - 25 of 34
• ### Analyses and comparisons of geometrical-based channel model arisen from scatterers on a hollow-disc for outdoor and indoor wireless environments

Publication Year: 2012, Page(s):2775 - 2786
Cited by:  Papers (2)
| |PDF (993 KB)

In this study, the authors investigate geometrically based statistical channel models for outdoor and indoor propagation environments. These models idealise the scatterers laying on a hollow-disc centred around the mobile station with these scatterers concentrating in a uniformly shaped spatial density. The joint probability density functions (pdfs) of angle of arrive (AoA)/time of arrive (ToA) an... View full abstract»

• ### Throughput analysis for cognitive radio networks with multiple primary users and imperfect spectrum sensing

Publication Year: 2012, Page(s):2787 - 2795
Cited by:  Papers (17)
| |PDF (566 KB)

In cognitive radio networks, the licensed frequency bands of the primary users (PUs) are available to the secondary user (SU) provided that they do not cause significant interference to the PUs. In this study, the authors analysed the normalised throughput of the SU with multiple PUs coexisting under any frequency division multiple access communication protocol. The authors consider a cognitive ra... View full abstract»

• ### Secure joint source-channel coding with interference known at the transmitter

Publication Year: 2012, Page(s):2796 - 2808
Cited by:  Papers (5)
| |PDF (421 KB)

In this study, the problem of transmitting an independent and identically distributed (i.i.d.) Gaussian source over an i.i.d. Gaussian wire-tap channel, with an i.i.d. Gaussian known interference available at the transmitter is considered. The intended receiver is assumed to have a certain minimum signal-to-noise ratio (SNR) and the eavesdropper is assumed to have a strictly lower SNR compared to ... View full abstract»

• ### Transmission of wired and wireless signals employing a hybrid radio-over-fibre passive-optical-networkbased on dual quadrupling-frequency

Publication Year: 2012, Page(s):2809 - 2815
| |PDF (630 KB)

A novel full duplex cost-effective hybrid radio-over-fibre passive-optical-network based on external modulation of a distributed feedback laser diode and dual-drive Mach-Zehnder modulator with multi-wavelength output characteristic is proposed and experimentally demonstrated. Baseband non-return-to-zero (BB-NRZ) signals, radio-frequency NRZ (RF-NRZ) signals, as well as RF orthogonal frequency divi... View full abstract»

• ### Delay controlled proportional fair scheduling in Rayleigh fading wireless channel

Publication Year: 2012, Page(s):2816 - 2824
| |PDF (529 KB)

In this study, the authors consider a delay control problem with proportional fair scheduling in time-varying wireless channels. For proportional fairness of transmission rates among users, a congestion control scheme is proposed for guaranteeing both throughput and delay of the wireless network. Specifically, a scheduling weight is introduced to control queue lengths without degrading the through... View full abstract»

• ### Integration of unicast and multicast scheduling in a two-stage switch architecture with low scheduling overhead

Publication Year: 2012, Page(s):2825 - 2832
Cited by:  Papers (1)
| |PDF (716 KB)

This study deals with the scalability problems induced by high complexity of integrated scheduling for high-speed switches, and presents a simple two-stage integrated scheduling algorithm that supports both unicast and multicast traffic simultaneously. The first stage of the switching fabric performs switching for unicast traffic and load-balancing for multicast traffic, whereas the second stage p... View full abstract»

• ### Effect of interpolation filter in digital quadrature amplitude modulation signal resampling

Publication Year: 2012, Page(s):2833 - 2839
Cited by:  Papers (1)
| |PDF (256 KB)

In this study, a closed-form equation is derived which relates the mean-squared error (MSE) to the frequency response of the interpolation filter. Effects of additive white Gaussian noise and timing jitter on the MSE are accounted for in the equation. By using properties of the Nyquist signalling pulse, a simple approximation to the MSE equation is obtained, which is found to be accurate over the ... View full abstract»

• ### Simple low-complexity detection schemes for M-ary quadrature amplitude modulation spatial modulation

Publication Year: 2012, Page(s):2840 - 2847
Cited by:  Papers (4)
| |PDF (531 KB)

In this study, the authors propose a simple low-complexity detection scheme for Nt×NrM-ary quadrature amplitude modulation spatial modulation that exhibits a much lower computational complexity compared to the conventional maximum-likelihood (ML) detection scheme. The proposed simple low-complexity detection scheme firstly detects the transmitted s... View full abstract»

• ### Throughput-based rate and power control for cognitive radio networks with receive diversity and error control

Publication Year: 2012, Page(s):2848 - 2854
Cited by:  Papers (2)
| |PDF (377 KB)

In this study, the cognitive radio (CR) networks are considered where the user can be categorised into the primary user (PU) and the secondary user (SU). A throughput-based rate and power control algorithm is proposed to find each SU's transmitting power and transmission rate that meet the throughput requirement of each SU for the CR networks with receiver diversity and error control. The proposed... View full abstract»

• ### Least-squares support vector machine-based learning and decision making in cognitive radios

Publication Year: 2012, Page(s):2855 - 2863
Cited by:  Papers (4)
| |PDF (484 KB)

Cognitive radio (CR) can improve system performance and increase its adaptation ability because of its high intelligence in configuring system parameters dynamically. The key of intelligence in CR is its learning capability. After comparing the conventional optimisation decision-making methods and the learning-based ones in intelligent reconfiguration in CR, this study proposes a general learning-... View full abstract»

• ### Reduced candidate mechanism for an algebraic code-excited linear-prediction codebook search

Publication Year: 2012, Page(s):2864 - 2869
Cited by:  Papers (4)
| |PDF (302 KB)

Underlain by algebraic codebook search, a reduced candidate mechanism (RCM) is proposed in this work to reduce the search complexity required. To begin with, the contribution made by each pulse pertaining to each track is evaluated, and then the hit probability of the top pulses in terms of contribution against the optimal pulses identified by a full search is found. Based upon such analysis, the ... View full abstract»

• ### Maximum-likelihood receivers for synchronous fast frequency-hopped multiple-access M-ary frequency-shift-keying systems over frequency-selective Rician-fading channels

Publication Year: 2012, Page(s):2870 - 2878
Cited by:  Papers (1)
| |PDF (421 KB)

In this study, the performance of a synchronous fast frequency-hopped multiple-access (MA) M-ary frequency-shift-keying system employing maximum-likelihood (ML) method over either frequency-selective Rician- or Rayleigh-fading channels is investigated. The ML receiver structures are derived and analysed. It is assumed that all the signals arrive at a receiver with the same power strength an... View full abstract»

• ### Capacity of millimetre-wave multiple-input multiple-output channels in a conference room

Publication Year: 2012, Page(s):2879 - 2885
Cited by:  Papers (10)
| |PDF (670 KB)

Based on the ray-tracing technique, the 2×2 multiple-input multiple-output (MIMO) channel capacity is examined for millimetre-wave propagation channels between two stations on a table in a conference room. This study focuses on the contributions of reflectors in enhancing the MIMO capacity with small antenna spacings. The effect of each class of reflectors (front/rear/left/right wall or cei... View full abstract»

• ### Factors influencing broadband transmission characteristics of underground low-voltage distribution networks

Publication Year: 2012, Page(s):2886 - 2893
Cited by:  Papers (2)
| |PDF (549 KB)

The established transmission analysis, already used to treat other overhead distribution and transmission power grid networks in Lazaropoulos and Cottis (2009, 2012), is now implemented to examine the factors influencing transmission characteristics of low-voltage/broadband over power lines (LV/BPL) channels associated with underground power distribution networks. The novelty of this study is thre... View full abstract»

• ### Imperfect spectrum sensing for partial spectrum-shared licensed networks

Publication Year: 2012, Page(s):2894 - 2899
| |PDF (370 KB)

This study considers a scenario where two licensed networks share spectrum partially and opportunistically based on sensing of cognitive radios. The authors' main contribution is a discrete-time Markov chain analysis characterising the impact of imperfect sensing and sensing periodicity on the network performance. A cross-layer design framework is also developed, where the parameters in spectrum s... View full abstract»

• ### Transmission of 60 GHz wired/wireless based on full-duplex radio-over-fibre using dual-sextupling frequency

Publication Year: 2012, Page(s):2900 - 2906
Cited by:  Papers (1)
| |PDF (583 KB)

A novel full-duplex radio-over-fibre dual-sextupling frequency system with thin-film filter (TFF) was proposed and simultaneously demonstrated. A light wave generated by a distribution feedback laser diode (DFB-LD) is modulated by an RF signal to generate optical sidebands. This system used a dual-drive LiNbO3 Mach-Zehnder modulator (DD-LN-MZM) and an optical TFF to generate dual-sextupling freque... View full abstract»

• ### Reversed Stackelberg bandwidth-sharing game for cognitive multi-hop cellular networks

Publication Year: 2012, Page(s):2907 - 2913
Cited by:  Papers (2)
| |PDF (292 KB)

Multi-hop relaying cellular network (MCN) is a recently proposed architecture to preserve the advantages of traditional single-hop cellular networks and ad hoc relaying networks. In MCNs, efficient bandwidth management plays an important role in determining network performance. In this study, a new cognitive radio bandwidth-sharing scheme is proposed based on the reversed Stackelberg game m... View full abstract»

• ### Relay-assisted transmission in free-space optical communication - RETRACTED

Publication Year: 2012, Page(s):2914 - 2921
| |PDF (22 KB)

[This paper has been withdrawn by the publisher.] In recent years, the demand for the use of free-space optical (FSO) communication channel has increased. For link ranges longer than 1 km, atmospheric turbulence-induced fading becomes major performance limiting factor in FSO systems. The relay-assisted transmission is used as powerful fading mitigation tool in atmospheric turbulence channels. Both... View full abstract»

• ### Super-orthogonal trellis-coded spatial modulation

Publication Year: 2012, Page(s):2922 - 2932
Cited by:  Papers (10)
| |PDF (942 KB)

Spatial modulation (SM), which employs the indices of multiple transmit antennas to transmit information in addition to the conventional M-ary signal constellations, is a novel transmission technique that has been proposed for multiple-input multiple-output systems. In this study, a new class of space-time trellis codes, called super-orthogonal trellis-coded SM (SOTC-SM), is proposed. The... View full abstract»

• ### Heuristic algorithm based on multicriteria analysis for selection of first mile access in standard integrated services digital broadcasting terrestrial

Publication Year: 2012, Page(s):2933 - 2940
| |PDF (569 KB)

Technologies used to link the end-user to a telecommunication infrastructure have been growing over time because of the consolidation of new access technologies. Moreover, the arrival of new tools for information dissemination, such as interactive digital TV, creates a bidirectional element, capable of connecting the end-user to telecommunications networks through access technologies such as world... View full abstract»

• ### Performance analysis of protograph-based low-density parity-check codes with spatial diversity

Publication Year: 2012, Page(s):2941 - 2948
Cited by:  Papers (10)
| |PDF (454 KB)

In wireless communications, spatial diversity techniques, such as space-time block code and single-input multiple-output (SIMO), are employed to strengthen the robustness of the transmitted signal against channel fading. This article studies the performance of protograph-based low-density parity-check (LDPC) codes with receive antenna diversity. The authors first propose a modified version of the ... View full abstract»

• ### Hybrid broadcasting scheme with low waiting time and buffer requirement for video-on-demand services

Publication Year: 2012, Page(s):2949 - 2956
| |PDF (761 KB)

This work proposes a hybrid broadcasting method, which combines the concepts of the enhanced recursive frequency splitting and reverse fast broadcasting methods. Benefiting from the two aforementioned methods, the proposed hybrid method holds two advantages of low waiting time and buffer requirement, respectively. Compared with the previous methods, the proposed method not only preserves low buffe... View full abstract»

• ### Taylor approximation pricing for K-user multiple-input multiple-output (MIMO) interference channels

Publication Year: 2012, Page(s):2957 - 2967
Cited by:  Papers (2)
| |PDF (372 KB)

This study considers the immense problem of sum rate maximisation in K-user multiple-input multiple-output interference channels (IFC). In order to address this problem, the authors propose an iterative Taylor approximation algorithm to find the optimal transmit covariance matrices, where each user maximises the sum rate function through Taylor expansion. Owing to the distributed nature of ... View full abstract»

• ### Channel-independent weighted bit-flipping decoding algorithm for low-density parity-check codes

Publication Year: 2012, Page(s):2968 - 2973
Cited by:  Papers (4)
| |PDF (570 KB)

In this study, a new method for improving hard-decision bit-flipping (BF) decoding is proposed for low-density parity-check codes. The flipping criterion is derived theoretically from the soft-decision belief-propagation decoding algorithm. The proposed BF decoding algorithm is channel independent and is improved by introducing a more efficient method for computing the reliability of the parity ch... View full abstract»

• ### Capacity analysis of multicast transmission schemes in a spectrum-sharing scenario

Publication Year: 2012, Page(s):2974 - 2979
Cited by:  Papers (1)
| |PDF (252 KB)

In this study, the authors consider the asymptotic capacity of wireless multicast and unicast transmission schemes in a spectrum-sharing system. In these schemes, a secondary access point (SAP) utilises the licensed spectrum of an active primary user (PU) to send a common information to multiple secondary users simultaneously, as long as the interference power inflicted on the PU is less than a pr... 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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