40 research outputs found

    Joint Optimal Design for Outage Minimization in DF Relay-assisted Underwater Acoustic Networks

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    This letter minimizes outage probability in a single decode-and-forward (DF) relay-assisted underwater acoustic network (UAN) without direct source-to-destination link availability. Specifically, a joint global-optimal design for relay positioning and allocating power to source and relay is proposed. For analytical insights, a novel low-complexity tight approximation method is also presented. Selected numerical results validate the analysis and quantify the comparative gains achieved using optimal power allocation (PA) and relay placement (RP) strategies.Comment: 5 pages, 2 figures; accepted to IEEE Communications Letters 201

    Cooperative Communication over Underwater Acoustic Channels

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    As diverse and data-heavy underwater applications emerge, demanding requirements are further imposed on underwater wireless communication systems. Future underwater wireless communication networks might consist of both mobile and stationary nodes which exchange data such as control, telemetry, speech, and video signals among themselves as well as a central node located at a ship or onshore. The submerged nodes, which can, for example, take the form of an autonomous underwater vehicle/robot or diver, can be equipped with various sensors, sonars, video cameras, or other types of data acquisition instruments. Innovative physical layer solutions are therefore required to develop efficient, reliable, and high-speed transmission solutions tailored for challenging and diverse requirements of underwater applications. Building on the promising combination of multi-carrier and cooperative communication techniques, this dissertation investigates the fundamental performance bounds of cooperative underwater acoustic (UWA) communication systems taking into account the inherent unique characteristics of the UWA channel. We derive outage probability and capacity expressions for cooperative multi-carrier UWA systems with amplify-and-forward and decode-and-forward relaying. Through the derived expressions, we demonstrate the effect of several system and channel parameters on the performance. Furthermore, we investigate the performance of cooperative UWA systems in the presence of non-uniform Doppler distortion and propose receiver designs to mitigate the degrading Doppler effects

    D13.2 Techniques and performance analysis on energy- and bandwidth-efficient communications and networking

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    Deliverable D13.2 del projecte europeu NEWCOM#The report presents the status of the research work of the various Joint Research Activities (JRA) in WP1.3 and the results that were developed up to the second year of the project. For each activity there is a description, an illustration of the adherence to and relevance with the identified fundamental open issues, a short presentation of the main results, and a roadmap for the future joint research. In the Annex, for each JRA, the main technical details on specific scientific activities are described in detail.Peer ReviewedPostprint (published version

    Design of large polyphase filters in the Quadratic Residue Number System

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    Temperature aware power optimization for multicore floating-point units

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