Search results for "wireless communication"

Energy-Efficient Resource Optimization with Wireless Power Transfer for Secure NOMA Systems

2018

In this paper, we investigate resource allocation algorithm design for secure non-orthogonal multiple access (NOMA) systems empowered by wireless power transfer. With the consideration of an existing eavesdropper, the objective is to obtain secure and energy efficient transmission among multiple users by optimizing time, power and subchannel allocation. Moreover, we also take into consideration for the practical case that the statistics of the channel state information of the eavesdropper is not available. In order to address the optimization problem and its high computational complexity, we propose an iterative algorithm with guaranteed convergence to deliver a suboptimal solution for gene…

Self-configuring multipath intra-mesh infrastructure QoS based routing

2016

International audience; Multi-path routing concept was largely exploited in wireless networks to provide benefits such as fault tolerance, load balancing, performance improvement in terms of latency, etc. In this paper, we propose a multi-path routing based protocol named MP-IMRR (Multi-path Intra-Mesh infrastructure Routing protocol) to improve our previously defined QoS based routing protocol for wireless mesh networks (i.e. IMRR). MP-IMRR is defined in order to achieve better reactivity and faster recovery from eventual route failures than the IMRR protocol by adopting the backup routes concept. Besides, given the complexity increase while considering network management systems, we adopt…

Fading mitigation coding techniques for space to ground free space optical communications

2014

In this manuscript, a Geostationary satellite-toground Free Space Optics (FSO) downlink channel model has been implemented, which is able to predict temporal irradiance fluctuations caused by scintillation at a wide range of turbulence conditions and for different values of the zenith angle. In order to mitigate fading events that occur in FSO communications, we have also tested the performance of three different families of Rateless Codes (Luby Transform, Raptor and RaptorQ) into our model and found that RaptorQ is the best candidate to mitigate errors in FSO links. Keywords— Optical Wireless Communications; Space-toGround FSO links, time-series, rateless codes; fading mitigation

Fading mitigation coding techniques for space to ground free space optical communications

2014

Propagation Channels for mmWave Vehicular Communications : State-of-the-art and Future Research Directions

2018

Vehicular communications essentially support automotive applications for safety and infotainment. For this reason, industry leaders envision an enhanced role for vehicular communications in the fifth generation of mobile communications technology. Over the years, the number of vehicle- mounted sensors has increased steadily, which potentially leads to more volume of critical data communications in a short time. Also, emerging applications such as remote/autonomous driving and infotainment such as high-definition movie streaming require data-rates on the order of multiple Gb/s. Such high data rates require a large system bandwidth, but very limited bandwidth is available in the sub-6 GHz cel…

Fading mitigation coding techniques for space to ground free space optical communications (Euro Med Telco 2014)

2014

In this manuscript, a Geostationary satellite-toground Free Space Optics (FSO) downlink channel model has been implemented, which is able to predict temporal irradiance fluctuations caused by scintillation at a wide range of turbulence conditions and for different values of the zenith angle. In order to mitigate fading events that occur in FSO communications, we have also tested the performance of three different families of Rateless Codes (Luby Transform, Raptor and RaptorQ) into our model and found that RaptorQ is the best candidate to mitigate errors in FSO links.

Routing Algorithm for Maximizing Lifetime of Wireless Sensor Network for Broadcast Transmission

2018

In the article we discuss solutions of the maximum lifetime broadcasting problem in wireless sensor networks. Due to limited energy resources of the network nodes to find an optimal transmission route of the broadcasted data we minimize the maximum energy consumed by the nodes. We give an analytical solution of the problem in one dimensional regular sensor network for the point-to-point and point-to-multipoint data transmission scheme. We show that in such a network, when the cost of data transmission is a polynomial function of distance between transmitter and receiver, there exist solutions with an equal energy, i.e., all nodes of the network consume the same amount of energy. We assume t…

A limited feedback scheme based on spatially correlated channels for coordinated multipoint systems

2012

High spectral efficiency can be achieved in the downlink of multi-antenna coordinated multi-point systems provided that the multiuser interference is appropriately managed at the transmitter side. For this sake, downlink channel information needs to be sent back by the users, thus reducing the rate available at the uplink channel. The amount and type of feedback information required has been extensively studied and many limited feedback schemes have been proposed lately. A common pattern to all of them is that achieving low rates of feedback information is possible at the cost of increasing complexity at the user side and, sometimes, assuming that some statistics of the channel are known. I…

Energy-aware design for wireless mesh networks

2014

International audience; Wireless mesh networks (WMNs) are the next step in the development of the wireless architecture, delivering wireless services for a large variety of users in personal, local, campus, and metropolitan areas. Energy efficiency solutions are becoming more vital for both local access networks and wireless networks and Green IT has attracted a considerable attention. However, the application of green network for wireless mesh networks has seldom been described in the literature. However, WMNs infrastructure devices are always active. Thus, during lower traffic periods the energy consumption is the same as in busy hours, while it would be possible to save a large amount of…

Designing Features for Fido: What Makes Animal-Computer Interaction So Different From Human-Computer Interaction?

2013

Lehtonen, Jaana Designing Features for Fido: What Makes Animal-Computer Interaction So Dif-ferent From Human-Computer Interaction? Jyväskylä: University of Jyväskylä, 2013, 21 p. Information Systems Science, Bachelor’s thesis Supervisor: Kuparinen, Liisa Animal-computer interaction aims to allow animals to interact not only with computers but their owners and other humans through computerised interfaces. This thesis studies the existing research on the main characteristics of ani-mal-computer interaction and what sets it apart from human-computer interac-tion. The main focus is on recognising and defining different kinds of chal-lenges affecting the development of tools and systems for anim…