Search results for "Computer Science::Information Theory"
showing 10 items of 272 documents
Analysis of the Non-Transparent In-Band Relays in the IEEE 802.16 Multi-Hop System
2010
This paper presents extensive dynamic simulations of the non-transparent in-band relays working in the distributed scheduling mode. The simulation results show that in-band relays can improve noticeably the spectral efficiency without acquiring an additional radio spectrum. Also, packet transmission delays become smaller. An important outcome of the dynamic simulations is that it is very crucial to choose a correct relay zone size where the base station and relay nodes exchange data. Otherwise, throughput fairness of the whole system declines. It indicates an importance of the relay zone size adjustment algorithm that the base station must run.
On-body and off-body transmit power control in IEEE 802.15.6 scheduled access networks
2014
Wireless Body Area Networks (WBANs) have received much attention due to the possibility to be used in healthcare applications. For these applications, energy saving is a critical issue, as in many cases, batteries cannot be easily replaced. A transmit power control scheme, able to adapt to the variations of the wireless body channel, will allow consistent energy saving and longer battery life. In this paper we propose a transmit power control scheme suitable for IEEE 802.15.6 narrowband scheduled access networks, in which the transmission power is modulated frame by frame according to a run-time estimation of the channel propagation conditions. A simple and effective line search algorithm i…
Development of a Matlab Toolbox for Mobile Fading Channel Simulators
2007
Masteroppgave i informasjons- og kommunikasjonsteknologi 2007 – Høgskolen i Agder, Grimstad Knowledge of channel behaviours in mobile radio communication is extensively recommended for the study of transmitter/receiver performances. Our intention in this master's thesis is to develop various kinds of mobile fading channel simulators using Matlab. The developed channel simulators were combined into a user-friendly toolbox from which users can easily select well-known channel models to test and to study the performance of mobile communication systems. The toolbox can be integrated into the new release of Matlab software. The toolbox contains channel simulators for spatial shadowing processes,…
Multiplexing of encrypted data using fractal masks
2012
In this Letter, we present to the best of our knowledge a new all-optical technique for multiple-image encryption and multiplexing, based on fractal encrypting masks. The optical architecture is a joint transform correlator. The multiplexed encrypted data are stored in a photorefractive crystal. The fractal parameters of the key can be easily tuned to lead to a multiplexing operation without cross talk effects. Experimental results that support the potential of the method are presented.
"Table 3" of "Search for contact interactions and large extra dimensions in dilepton events from pp collisions at sqrt(s) = 7 TeV with the ATLAS dete…
2013
Expected and observed 95% C.L. lower limits on the contact interaction energy scale LAMBDA for the dielectron and dimuon channels, as well as for the combination of those channels. Results are provided for constructive and destruc- tive interference as well as different choices of flat priors.
"Table 1" of "Search for scalar leptoquarks in $pp$ collisions at $\sqrt{s} = 13$ TeV with the ATLAS experiment"
2016
Normalisation factors for the main backgrounds obtained from the combined fit in each of the channels. The total uncertainty is given.
"Table 29" of "Search for supersymmetry in final states with jets, missing transverse momentum and one isolated lepton in sqrt{s} = 7 TeV pp collisio…
2016
Effective mass in the 4-jet tight signal region (electron channel).
"Table 27" of "Search for supersymmetry in final states with jets, missing transverse momentum and one isolated lepton in sqrt{s} = 7 TeV pp collisio…
2016
Effective mass in the 4-jet loose signal region (electron channel).
On the Statistical Properties of Phase Crossings and Random FM Noise in Double Rayleigh Fading Channels
2016
In this paper, we study the statistics of phase processes and random frequency modulation (FM) noise encountered in double Rayleigh fading channels. The Rayleigh processes making up the double Rayleigh channel are assumed to be independent but not necessarily identically distributed. The Doppler power spectral densities of these processes are supposed to be symmetric about the carrier frequency. Under these fading conditions, we derive first an expression for the joint probability density function (jpdf) of the phase process and its rate of change. Capitalizing on this jpdf formula, we then investigate the probability density function (pdf) and cumulative distribution function (cdf) of rand…
Statistical Properties of Double Hoyt Fading With Applications to the Performance Analysis of Wireless Communication Systems
2018
In this paper, we investigate the statistical properties of double Hoyt fading channels, where the overall received signal is determined by the product of two statistically independent but not necessarily identically distributed single Hoyt processes. Finite-range integral expressions are first derived for the probability density function (PDF), cumulative distribution function (CDF), level-crossing rate (LCR), and average duration of fades of the envelope fading process. A closed-form approximate solution is also deduced for the LCR by making use of the Laplace approximation theorem. Applying the derived PDF of the double Hoyt channel, we then provide analytical expressions for the average…