Search results for "distributed systems"
showing 8 items of 38 documents
Analysis on channel bonding/aggregation for multi-channel cognitive radio networks
2010
Paper presented at the 2010 European Wireless Conference, Lucca. (c) 2010 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works. Paper also available from the publisher: http://dx.doi.org/10.1109/EW.2010.5483492 Channel bonding/aggregation techniques, which assemble several channels together as one channel, could be used in cognitive radio networks for the purpose of achieving better bandwidth utilizatio…
Evaluation of international standards for ECG-recording and storage for use in tele-medical services
2006
This report is written to clarify which of the international standards for ECG recordings that can be used in tele-medical services, where the recordings should be transmitted by wireless telecommunication facilities and finally stored as information integrated into the patients Electronic Health Record (EHR). Some principals for recording, transmission and storage of digital vital signs parameters are highlighted and important aspects of wireless communication of recorded signals from biomedical sensors are described, in order to understand the significance and differences in the storing formats to be used. Even if most of the relevant standards are not yet ratified (the last meeting in IS…
The Design of Sum-of-Cisoids Rayleigh Fading Channel Simulators Assuming Non-Isotropic Scattering Conditions
2010
Published version of an article from the journal: IEEE Transactions on Wireless Communications. .(c) 2010 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works. Article also available from the publisher: http://dx.doi.org/10.1109/twc.2010.04.091198 n this letter, we introduce the Riemann sum method (RSM) as an effective tool for the design of sum-of-cisoids (SOC) simulators for narrowband mobile Rayleigh…
Cooperative MAC design in multi-hop wireless networks: Part I: When source and destination are within the transmission range of each other
2010
Published version of an article from the journal: Wireless Personal Communications. The original publication is available at Spingerlink. http://dx.doi.org/10.1007/s11277-010-0072-y Cooperative communication is regarded as a promising technology in future 5G wireless networks to enhance network performance by exploiting time and/or space diversity via distributed terminals. In this paper, we propose a cooperative medium access protocol which addresses three key aspects of cooperative communications from MAC layer perspective, namely, when to cooperate, whom to cooperate with and how to protect ongoing cooperative transmissions. To further improve the protocol performance in dense networks, …
The influence of severity of fading on the statistical properties of the capacity of Nakagami-m channels with MRC and EGC
2010
Paper presented at the 2010 European Wireless Conference , Lucca Italy. (c) 2010 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works. Paper also available from the publisher: http://dx.doi.org/10.1109/EW.2010.5483507 In this article, we have studied the statistical properties of the capacity of Nakagami-m channels when spatial diversity combining, such as maximal ratio combining (MRC) and equal gain co…
Optimization of Linearized Belief Propagation for Distributed Detection
2020
In this paper, we investigate distributed inference schemes, over binary-valued Markov random fields, which are realized by the belief propagation (BP) algorithm. We first show that a decision variable obtained by the BP algorithm in a network of distributed agents can be approximated by a linear fusion of all the local log-likelihood ratios. The proposed approach clarifies how the BP algorithm works, simplifies the statistical analysis of its behavior, and enables us to develop a performance optimization framework for the BP-based distributed inference systems. Next, we propose a blind learning-adaptation scheme to optimize the system performance when there is no information available a pr…
Modeling and Mitigating Errors in Belief Propagation for Distributed Detection
2021
We study the behavior of the belief-propagation (BP) algorithm affected by erroneous data exchange in a wireless sensor network (WSN). The WSN conducts a distributed multidimensional hypothesis test over binary random variables. The joint statistical behavior of the sensor observations is modeled by a Markov random field whose parameters are used to build the BP messages exchanged between the sensing nodes. Through linearization of the BP message-update rule, we analyze the behavior of the resulting erroneous decision variables and derive closed-form relationships that describe the impact of stochastic errors on the performance of the BP algorithm. We then develop a decentralized distribute…
An Exact Solution for the Level-Crossing Rate and the Average Duration of Fades of the Envelope of Sum-of-Cisoids Processes
2012
Authors version of an article published in the journal: Procedia Technology. Also available from the publisher at: http://dx.doi.org/10.1016/j.protcy.2012.03.004 Sum-of-cisoids (SOC) processes provide a physically and numerically appealing framework for the modelling and simulation of a wide class of mobile radio channels. This paper is concerned with the problem of finding a general solution for the level-crossing rate (LCR) and the average duration of fades (ADF) of the envelope of SOC processes. Exact expressions are derived for the LCR and the ADF by taking into account that the inphase component, the quadrature component, and the time derivatives of the inphase and quadrature component…