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Source direction of arrival (DOA) estimation is one of the challenging problems in many applications. Such applications can be seen in wireless communications, radar, radio astronomy, sonar and navigation. The resolution of a source direction of arrival estimation can be enhanced by an array antenna system with innovative signal processing. Super resolution techniques take the advantage of array antenna...
In order to achieve the ubiquitous Internet, connection to the network must be available everywhere, at anytime, without disruption of service. In order to reach this objective, communications are now considered necessary and will play an increasing role in the Intelligent Transportation Systems (ITS) era. As train speeds increase (up to 350 km/h), wireless communications between devices on the train...
This paper presents a testbed platform to demonstrate and validate spectrum opportunity identification and spectrum selection functionalities in Opportunistic Networks (ONs). The hardware component of the testbed is based on reconfigurable devices able to transmit and receive data at different operating frequencies, which are dynamically configured. The software component has been developed to perform...
Service providers and users are located at the opposite ends of the Gigabit passive optical access network (GPON) channel [1] and hence fair resource allocation and control for both service providers and users can be very challenging. This paper introduces an integrated scheme for optimizing resource allocation in multi-operator GPON access networks.
Future generations ensuing expectations will exert integration of heterogeneous networks. Networks ought to prefer seamless handoff. A Node in mobility changes its point of contact when moves from one cell to another which has to be done uniquely. This is termed as vertical handoff. Handoff control amongst different networks has become a major issue. Several handoff algorithms has been proposed for...
Indoor positioning has focused the interest of researchers for years. Although there are several techniques proposed, they are difficult to reproduce and consequently to contrast and improve. This paper presents a modular location platform, which enhances the SoftMAC implementation in Linux with positioning capabilities. This platform can be deployed in any device running Linux kernel 2.6 or higher...
In this article, we analyze the performance of a downlink (DL) direct sequence code division multiple access (DS-CDMA) system aided by cooperative diversity for the bad urban power-delay distribution pertaining to ITV-R. The considered DL system supports multiuser transmitter preprocessing (MUTP) to mitigate the DL multiuser interference (MUI) at the relay stations (RSs) and mobile stations (MSs)...
The recent advances in wireless mesh communications technologies have given the rise to evolve maritime wireless mesh networks (MWMNs). Maritime users require more high data rate applications, where the cost associated with the conventional satellite and the legacy systems that provide low data rate applications have posed major limitations for the emergence of MWMNs. Besides, the network architecture...
Disruption Tolerant Networks (DTNs) can be characterized by intermittent network connectivity and unguaranteed end-to-end paths. Replication based routing is often used to improve the message delivery but it suffers from high traffic overhead and uncontrolled forwarding paths. In this paper, we propose a Multi-Policy Link State Routing (MPLSR) protocol to enable message forwarding using controlled...
This paper considers an asynchronous distributed power allocation scheme for sum-rate-maximization under cognitive Gaussian multiple access channels (GMACs), where primary users and secondary users may communicate under mutual interference with the Gaussian noise. Formulating the problem as a standard nonconvex quadratically constrained quadratic problem (QCQP) provides a simple distributed method...
In this paper, reduced complexity channel estimation techniques that was first proposed in case of Single Input Single Output Orthogonal Frequency Division Multiplexing (SISO-OFDM) is generalized in case of multiple-input multiple-output — OFDM (MIMO-OFDM) systems. The impact of complexity reduction is analyzed through floating point simulation, fixed point simulation and FPGA implementation using...
This work investigates the theoretical capacity achievement of tripole array multi-input multi-output (MIMO) systems in wide angular spread environment using the correlation channel model for Rayleigh fading channels. Preliminary Monte Carlo simulation results show high capacity achievement for azimuth angular spread environment for a tripole dipole array with the tripole elements located uniformly...
Epidemic broadcasting, in which an infected node repeatedly forwards a copy of a message to other nodes, realizes one-to-many communication in delay/disruption-tolerant networks. In epidemic broadcasting, the key is to control the number of message forwardings among nodes while maintaining a short message delivery time in the network. In this paper, we present a novel idea for improving the performance...
In this paper, we propose a base station selection and resource allocation model for OFDMA macro-femtocell networks. Dense deployment of femtocells can cause severe interference for femto and macro users alike. Our framework assumes hybrid-access femtocells to grant access to public user in their vicinity and to reduce interference perceived by femto users. Full spectrum sharing is investigated for...
Effective intercell interference (ICI) mitigation has been identified as a key challenge for emerging OFDMA cellular technologies such as Long Term Evolution (LTE). In order to address this issue, mobile operators have adopted static Intercell Interference Coordination (ICIC) strategies, including Fractional Frequency Reuse (FFR), given their low complexity and easy implementation. However, recent...
A key task in Wireless Sensor Networks (WSNs) is to deliver specific information about a spatial phenomenon of interest. To this end, a few Sensor Nodes (SNs) sample the phenomenon and transmit the acquired samples, typically multihop, to the application through a gateway called sink. Many applications require the spatial sampling to be accurate and the delivery to be reliable. However, providing...
The main wireless technology used for events sensing and data collection is wireless sensor devices. These sensors are mounted on vehicles or in the roadside to send data collected periodically or upon incident detection. In this latter case, ensuring low transmission delay from the detector sensor to WSNs gateway is a real challenge. Indeed, faster notification of the Traffic Management System (TMS)...
Wireless sensor network has recently become an area of attractive research interest. It consists of low-cost, low power, and energy-constrained sensors responsible for monitoring a physical phenomenon and reporting to sink node where the end-user can access the data. Saving energy and therefore extending the wireless sensor network lifetime, involves great challenges. For these purposes, clustering...
Increasing mobility and collaboration are key aspects of ubiquitous communication. Mobile collaborative applications require novel schemes for group communication that actively support closed collaborations in wireless scenarios. Existing group communication protocols do not sufficiently support, for instance, temporary losses of connections with the group. In this paper, we present Moversight, a...
Video applications are becoming the key services in today's networks (both fixed networks and mobile networks). Consideration of video service quality has become essential to provide the end users with satisfying Quality of Experience (QoE). In order to evaluate and manage the video quality, methods for QoE assessment are desired to estimate the service quality perceived by the end users. In this...
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