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Conventional antennas in single-antenna terminals that resonate at frequencies lower than 1 GHz usually rely on the chassis as the main radiator. To effectively exploit chassis excitation for MIMO terminals, each of the multiple antennas is required to excite one distinct chassis mode. However, in today's terminals, there is typically only one chassis mode that can radiate efficiently at frequenci
From our experimental investigation of multiple-antenna performance and user impact of a realistic mobile terminal setup, we find that apart from the important loss of efficiency due to the user hand, the impact on the individual antennna elements and the directional impact of the user body shadowing have quite small influence on the diversity and capacity performance. It is found that the top and
A simple and intuitive metric of multiplexing efficiency is proposed for evaluating the performance of MIMO antennas in the spatial multiplexing mode of operation. Apart from gaining valuable insights into the impact of antenna efficiency, efficiency imbalance and correlation on multiplexing performance, the metric is particularly useful for antenna engineers whose goal is to achieve the optimum a
We consider the problem of approximating functions that arise in wave-equation imaging by sums of wave packets. Our objective is to find sparse decompositions of image functions, over a finite range of scales. We also address the naturally connected task of numerically approximating the wavefront set. We present an approximation where we use the dyadic parabolic decomposition, but the approach is
Characteristic mode analysis provides unparalleled insights into designing high performance multiple-input multiple-output (MIMO) terminal antennas at frequencies where the antenna elements are constrained to be electrically small. Conventionally, an electrically small single-antenna utilizes the fundamental characteristic mode of the terminal chassis to obtain sufficient bandwidth while maintaini
Traffic measurements in broadband access networks are crucial from several points of view. A better understanding of traffic patterns can lead to more efficient network design, which leads to energy and cost savings for the operator and improved end user services. This paper reports on selected traffic measurement results from the Celtic TRAMMS project. The measurements were performed in broadband
Ontologies, formal knowledge representation, and reasoning are technologies that have begun to gain substantial interest in recent years. We present a high-level declarative approach to writing application programs for specific ontologies, based on viewing the ontology as a domain-specific language.Our approach is based on declarative meta-compilation techniques. We have implemented a tool using t
This demonstration presents a highperformance syntactic and semantic dependency parser. The system consists of a pipeline of modules that carry out the tokenization, lemmatization, part-of-speech tagging, dependency parsing, and semantic role labeling of a sentence. The system’s two main components draw on improved versions of a state-of-the-art dependency parser (Bohnet, 2009) and semantic role l
It has been proposed that six co-located antennas, namely three electric and three magnetic dipoles, can offer up to a six-fold capacity increase in wireless channels, relative to that of single antennas. In other words, six degrees of freedom (DOFs) can be supported by co-located six-port transmit and receive antenna arrays. However, due to the complexity in designing and measuring such a six-por
This paper presents a 3rd-order, 3-bit continuous time (CT) Delta-Sigma modulator for an LTE radio receiver. By adopting a return-to-zero (RZ) pulse in the innermost DAC, the modulator shows a reduced sensitivity to loop-delay variations, and the additional loop delay compensation usually needed in CT modulators can be omitted. The modulator has been implemented in a 65nm CMOS process, where it oc
With increasing usage of the Internet, energy consumption of network equipment has become a crucial challenge from both an economic and an environmental point of view. This paper combines users’ behavior of accessing the network with energy saving algorithms for energy-aware network equipment, and investigates potential energy savings in the access network. The study is based on a set of traffic d
Internet traffic from a fibre based residential access network is investigated concerning traffic volumes and link load. Also the cost of the services is analyzed. We show that 1 Mbps accesses subscribers maintain high loads, and that the price they pay per GB used is five times higher than the one paid by 100 Mbps access subscribers.
This paper describes an attempt to provide more intelligence to industrial robotics and automation systems. We develop an architecture to integrate disparate knowledge representations used in different places in robotics and automation. This knowledge integration framework, a possibly distributed entity, abstracts the components used in design or production as data sources, and provides a uniform
Excitation of the chassis enables single-antenna terminals to achieve good bandwidth and radiation performance, due to the entire chassis being utilized as the main radiator. In contrast, the same chassis excitation phenomenon complicates the design of multiple antennas for MIMO applications, since the same characteristic mode of the chassis may be effectively excited by more than one antenna, lea
Electromagnetic vector spherical waves have been used recently to model antenna-channel interaction and the available degrees of freedom in MIMO systems. However, there are no previous accounts of a method to estimate spherical wave coefficients from channel measurements. One approach for this, using a 3D positioner, is presented and analyzed in this letter. Measurement results are presented and d
Base station (BS) cooperative transmission is a promising technique to improve spectral efficiency of cellular systems, using which the channels become asymmetric in average gain. In this paper, we study the impact of the asymmetric channel gains on the performance of coherent cooperative transmission systems, when minimum mean square error (MMSE) and least square (LS) channel estimators are appli
The Theory of Characteristic Modes (TCM) has been applied to design high-performance MIMO antennas for mobile terminals. However, existing studies focus on free-space (FS) performance, which is mostly irrelevant in real usage. This paper investigates the performances of two TCM-based MIMO terminal antenna designs in 7 realistic user scenarios for frequencies below 1 GHz. Full-wave simulation resul
Litt S13 Kurslitteratur HIS S13 Historia: Kulturhistoria - nätbaserad masterskurs (7,5 p) Fastställd av historiska institutionens styrelse 2011-05-27. Green, Anna (2008). Cultural history. Basingstoke: Palgrave Macmillan. ISBN: 978-0-333- 98675-2. (163 s.) Ehn, Billy & Löfgren, Orvar (2001). Kulturanalyser. 2. omarb. uppl. Malmö: Gleerup. ISBN: 91- 40-63486-8. (180 s.) Kulturhistoriskt tema Varje
https://www.historiska.lu.se/media/utbildning/dokument/kurser/HISS13/20121/Litt_S13.pdf - 2026-05-31
Purpose: This study’s purpose is to examine if it’s possible through the Value Investing strategy The Acquirer’s Multiple to generate riskadjusted excess return during the period 2003-03-01 to 2016-03-01. Method: A study in the form of a quantitative method based on Tobias E. Carlisle formula The Acquirer’s Multiple with data extracted on a monthly basis from Thompson Reuters Datastream. Theory
