Sökning: "Wireless network"

Visar resultat 1 - 5 av 478 avhandlingar innehållade orden Wireless network.

1. 1. Wireless Broadcasting with Network Coding

   Författare :Lu Lu; Lars Kildehöj Rasmussen; Giuseppe Durisi; KTH; []
   Nyckelord :wireless broadcasting; relay-aided system; systematic binary deterministic rateless codes; random network coding; instantaneously decodable network coding;

   Sammanfattning : Wireless digital broadcasting applications such as digital audio broadcast (DAB) and digital video broadcast (DVB) are becoming increasingly popular since the digital format allows for quality improvements as compared to traditional analogue broadcast. The broadcasting is commonly based on packet transmission. LÄS MER

3. 2. Design and Performance of Diversity based Wireless Interfaces for Sensor Network Nodes

   Författare :Magnus Jobs; Anders Rydberg; Shi Cheng; Uppsala universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Wireless; Sensor; Network; WSN; Antenna; WISENET; Node; Diversity; Phased Array; Conformal; WBAN; Body Area; Engineering Science with specialization in Microwave Technology; Teknisk fysik med inriktning mot mikrovågsteknik;

   Sammanfattning : The main focus of the work presented in this licentiate thesis concerns antenna design, adaptive antenna control and investigation on how the performance of small wireless nodes can be increased by inclusion of multiple antennas. In order to provide an end-user suitable solution for wireless nodes the devices require both small form factor and good performance in order to be competitive on the marked and thus the main part of this thesis focuses on techniques developed to achieve these goals. LÄS MER

4. 3. Wireless Sensor Network Positioning Techniques

   Författare :Mohammad Reza Gholami; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; outer-approximations; Cram; Wireless sensor network; nonlinear and linear least squares; cooperative positioning; projection onto convex sets; maximum likelihood esti- mator;

   Sammanfattning : Position information is one of the key requirements for wireless sensor networks(WSNs). Since GPS receivers have drawbacks when used in low-power sensor nodes,mainly due to latency in position recovery and limited access to GPS satellites in indoor-type scenarios, extracting the position information by means of the network itself, so-called positioning or localization, has been considered an eective solution for the posi-tioning problem. LÄS MER

5. 4. Traffic Analysis, Modeling and Their Applications in Energy-Constrained Wireless Sensor Networks : On Network Optimization and Anomaly Detection

   Författare :Qinghua Wang; Tingting Zhang; Stefan Pettersson; Youzhi Xu; Yan Zhang; Mittuniversitetet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Wireless sensor network; traffic analysis; network optimization; anomaly detection; Computer and systems science; Data- och systemvetenskap;

   Sammanfattning : Wireless sensor network (WSN) has emerged as a promising technology thanks to the recent advances in electronics, networking, and information processing. A wide range of WSN applications have been proposed such as habitat monitoring, environmental observations and forecasting systems, health monitoring, etc. LÄS MER

7. 5. Broadband Wireless OFDM Systems

   Författare :Maxime Flament; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; channel model; 4th Generation Wireless 4GW ; shadowing; MMIC; WLAN; scenarios; mobile data; OFDM; turbo codes; propagation; license-exempt bands; coding; 60 GHz channel; broadband wireless; interference; Virtual Cellular Network VCN ; front-end;

   Sammanfattning : While the readiness of the telecommunication market and the users' need for broadband mobile data are not currently noticeable, a set of presented megatrends and scenarios suggest that broadband mobile data access will develop quickly in the next ten years. Identification of the potential frequency bands offering cheap and trouble-free wireless infrastructure is therefore an important step towards the definition of new air interfaces. LÄS MER