36 research outputs found
Powerline Kommunikation: Wesentliche Technologien um PLC in CE-GerÀte zu integrieren
In-house PLT (Powerline Telecommunication) enables new and highly convenient networking
functions without the need for additional cables on mains-powered devices. Since wireless
networks are not able to reach sufficient throughput between different rooms or even floors,
PLC is considered to be the ideal backbone home network medium, providing complementary
and seamless interaction with wireless networks.
The need to communicate information is not new. The historical overview of this thesis
compares the development of PLT to radio broadcast technologies. The consumer expects
technologies to operate without interferences. Today, there are coexistence problems between
these two technologies. Why does this happens, and how the problems can be resolved are the
main issues of this thesis.
Initial calculations of the channel capacity provide encouraging results for using the mains
cabling as a communication medium. Chapter 3 forecasts how PLT modems could develop in
the future. The usage of frequencies above 30 MHz will increase the throughput rate. Next, the
utilization of the 3rd wire (the protective earth) for communication enhances the coverage and
the reliability of powerline transmissions. The reception of common mode signals and the usage
of MIMO technologies enable 8 transmission paths between one pair of outlets, which
improves the performance of the bad, strongly attenuated channels.
Today, the main challenge for the mass deployment of PLT is the lack of harmonized international
standards on interoperability and electromagnetic interference. The absence of a standard
results in the undesirable situation of PLT modems interfering with technologies from
different vendors and also with radio applications. Solutions for solving these problems are
given in chapter 4 and chapter 5.
The approach of âSmart Notchingâ - monitoring the existence of receivable radio broadcast
stations at the time and location where a PLT modem is operating, received wide resonance in
the PLT and radio broadcast communities. âSmart Notchingâ, also called âDynamic Notchingâ
or âAdaptive Notchingâ is considered to be the key factor in solving the endless discussions
about the interferences to HF radio broadcast. Details on the creation of ETSI TS 102 578 and
the implementation of a demonstrator system is documented in chapter 5. Field tests conducted
together with the EBU verified the efficiency of the concept. The jointly executed tests by representatives
from the radio broadcast and the PLT communities became a historical event
which brought the two technologies, radio receivers and PLT modems, back into one house.
Finally, a vision of the future coordination of EMC and conclusions are presented.Heutige Modems zur Powerline Telekommunikation (PLT) können im Betrieb den Empfang
von Kurzwellen-Rundfunk beeintrÀchtigen, wenn Modem und Rundfunk-EmpfÀnger in
unmittelbarer Nachbarschaft betrieben werden. Eine neue Generation von PLT Modems, in
denen das Konzept von 'Smart Notching' - dem intelligenten EinfĂŒgen von LĂŒcken in das
Kommunikationsspektrum - implementiert ist, zeigt keine Interferenzen mit dem Empfang von
Rundfunkdiensten.
Das Rauschen auf der Niederspannungsinstallation enthÀlt neben sonstigen Signalen - durch
andere GerĂ€te hervorgerufen - aufgrund der Antennenwirkung Information ĂŒber Rundfunksender.
Beim âSmart Notchingâ erkennen PLT Modems am Betriebsort die Existenz von Rundfunksignalen,
indem sie das Signalspektrum auf der Netzleitung messen. Die Echtzeit-
Bewertung der aktuellen Situation am Betriebsort ermöglicht eine Adaption des PLT Systems.
Damit wird die Elektromagnetische VertrÀglichkeit nicht a priori (zum Herstellungs-Zeitpunkt)
durch Schirmung oder eine globale Reduktion des Sendepegels, sondern durch Design des
Verfahrens (welches wÀhrend des Betriebs angewendet wird) hergestellt.
Diese Doktorarbeit beschreibt nach einem kurzen Ăberblick zur Historie des Rundfunks
und der DatenĂŒbertragung ĂŒber das Energieverteilnetz Messungen zur Ermittlung der theoretischen
KanalkapazitĂ€t. AnschlieĂend wird ein Ausblick gegeben, wohin sich zukĂŒnftige PLT
Modems entwickeln werden. Dies sind vor allem der Frequenzbereich oberhalb von 30 MHz
sowie die Nutzung der dritten Kupferader in den Netzleitungen: der Schutzerde. Die Verwendung
von MIMO-Algorithmen (aus der kabellosen FunkĂŒbertragung (z.B. WiFi) bereits bekannt)
verbessert vor allem die Wahrscheinlichkeit, eine hohe Datenrate im GebÀude sicher zu
verteilen.
Sorge bereitet bei PLT ebenfalls die Koexistenz mit weiteren PLT-Systemen, sowie zu
xDSL. HierfĂŒr wird ein Vorschlag gemacht, um die Interferenzen zu nicht kompatiblen PLToder
DSL-Systemen zu vermeiden, ohne dass die Systeme sich gegenseitig gezielt Informationen
zusenden.
Das bereits oben erwĂ€hnte Konzept des âSmart Notchingâ wird detailliert erlĂ€utert und die
Implementierung eines Demonstrators auf FPGA-Basis dokumentiert. AbschlieĂend wird noch
beschrieben, wie âSmart Notchingâ gemeinsam mit der EBU getestet wurde und wie es seinen
Weg in die Welt der Standardisierung gefunden hat. Der Veröffentlichung des Standards ETSI
TS 102 578 wurde im Juli 2008 einstimmig von ETSI PLT zugestimmt
The impact of tumor metabolic activity assessed by F-FET amino acid PET imaging in particle radiotherapy of high-grade glioma patients
Selective uptake of (18)F-fluoro-ethyl-tyrosine (F-FET) is used in high-grade glioma (HGG) to assess tumor metabolic activity via positron emission tomography (PET). We aim to investigate its value for target volume definition, as a prognosticator, and associations with whole-blood transcriptome liquid biopsy (WBT lbx) for which we recently reported feasibility to mirror tumor characteristics and response to particle irradiation in recurrent HGG (rHGG)
Genomic Organization and Expression Demonstrate Spatial and Temporal Hox Gene Colinearity in the Lophotrochozoan Capitella sp. I
Hox genes define regional identities along the anteriorâposterior axis in many animals. In a number of species, Hox genes are clustered in the genome, and the relative order of genes corresponds with position of expression in the body. Previous Hox gene studies in lophotrochozoans have reported expression for only a subset of the Hox gene complement and/or lack detailed genomic organization information, limiting interpretations of spatial and temporal colinearity in this diverse animal clade. We studied expression and genomic organization of the single Hox gene complement in the segmented polychaete annelid Capitella sp. I. Total genome searches identified 11 Hox genes in Capitella, representing 11 distinct paralog groups thought to represent the ancestral lophotrochozoan complement. At least 8 of the 11 Capitella Hox genes are genomically linked in a single cluster, have the same transcriptional orientation, and lack interspersed non-Hox genes. Studying their expression by situ hybridization, we find that the 11 Capitella Hox genes generally exhibit spatial and temporal colinearity. With the exception of CapI-Post1, Capitella Hox genes are all expressed in broad ectodermal domains during larval development, consistent with providing positional information along the anteriorâposterior axis. The anterior genes CapI-lab, CapI-pb, and CapI-Hox3 initiate expression prior to the appearance of segments, while more posterior genes appear at or soon after segments appear. Many of the Capitella Hox genes have either an anterior or posterior expression boundary coinciding with the thoracicâabdomen transition, a major body tagma boundary. Following metamorphosis, several expression patterns change, including appearance of distinct posterior boundaries and restriction to the central nervous system. Capitella Hox genes have maintained a clustered organization, are expressed in the canonical anteriorâposterior order found in other metazoans, and exhibit spatial and temporal colinearity, reflecting Hox gene characteristics that likely existed in the protostomeâdeuterostome ancestor
A Statistical Model of the In-Home MIMO PLC Channel based on European Field Measurements
International audienceThe Multiple-Input Multiple-Output (MIMO) technique is well known in the field of wireless communications, and has recently been proposed to increase the capacity of in-home Power Line Communication (PLC) networks. MIMO PLC employs the Protective Earth in addition to the classical Line and Neutral wires, to form a multi-sensor transmission channel. By considering the additional reception of Common Mode signals, up to 2 simultaneous transmit ports and 4 receive ports can be considered. In order to develop new signal processing strategies optimally exploiting the MIMO propagation characteristics, and to evaluate their performance, accurate modeling of the transmission channel is necessary. This paper presents a comprehensive statistical model of the in-home MIMO PLC channel based on an extensive measurement data base collected in 6 European countries. The study first analyses the main MIMO PLC channel parameters, including path loss parameters and wideband parameters such as the delay spread, coherence bandwidth and small-scale statistics. A focus is then made on the MIMO correlation matrix, and its modelling using empirical statistical distributions. A fully parameterized channel model is then developed, with a particular emphasis on both the frequency fading structure of the transfer function and the correlation matrix between sub-channels. As a result, the proposed model generates random MIMO PLC channel realizations statistically representative of the experimental observations
MIMO PLC capacity and throughput analysis
International audienceMultiple input multiple output (MIMO) systems have been used for many years in the field of wireless communications. The huge increase in coverage and capacity offered by MIMO technology are the key benefits of using multiple sensors at the transmitter and receiver . Recently, MIMO technology has been applied in the context of power line communications (PLCs), with the aim of offering higher channel capacity and therefore larger system coverage, by including the use of the protective earth (PE) wire in addition to the line (L) and neutral (N) wires. SNR values observed in typical PLC scenarios can be much higher than in the case of a classical wireless communication. This high SNR condition is beneficial for MIMO transmission, as it ensures a high capacity gain with respect to single input single output (SISO) transmission, even if the channel presents a high degree of spatial correlation. This chapter is divided into two main sections. First, the PLC channel capacity offered by MIMO technology is analysed in details. The channel capacity provides an upper limit for achievable throughput and does not take system implementation or a particular MIMO scheme into consideration. The achievable throughput for different MIMO schemes in an OFDM system with adaptive modulation is then investigated
MIMO Power Line Communications: Narrow and Broadband Standards, EMC, and Advanced Processing
International audienceThis book on MIMO Power Line Communications is subdivided into five thematic parts. Part I looks at narrow and broadband channel characterization based on measurements from around the globe. Taking into account current regulations and electromagnetic compatibility, Part II describes MIMO signal processing strategies and related capacity and throughput estimates. Current Narrow- and Broadband PLC standards and specifications are described in the various chapters of Part III. Advanced PLC processing options are treated in Part IV, drawing from a wide variety of research areas such as beamforming/precoding, time reversal, multi-user processing and relaying. Finally, Part V contains Case Studies and Field Trials where the advanced technologies of tomorrow are put into practice today