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Recent work has shown that, with the help of the Theory of Characteristic Modes (TCM), minor modifications of the terminal chassis can facilitate the design of orthogonal MIMO antennas with viable bandwidth at frequencies below 1 GHz. Herein, a new framework is proposed to further exploit TCM to enhance the performance of the orthogonal MIMO antennas. By correlating the characteristic currents and
High-quality video is being increasingly delivered over Internet Protocol networks, which means that network operators and service providers need methods to measure the quality of experience (QoE) of the video services. In this paper, we propose a method to speed up the development of no-reference bitstream objective metrics for estimating QoE. This method uses full-reference objective metrics, wh
Abstract in UndeterminedThis article presents the development to reliably seal copper canisters containing the Swedish nuclear waste, using friction stir welding. To avoid defects and welding tool fractures, it is important to control the welding temperature within a span of 790–910 degrees C. A cascade controller is used to efficiently suppress fast power input disturbances reducing their impact on the temperature. The
In this paper, we study the performance of precoding schemes for cooperative transmission of multiple coherent base stations (BSs) that allow for overlapped clustering in a measured urban macrocellular environment at 2.66 GHz, in order to verify previous findings obtained by using simulated channel data. The evaluated precoding schemes include zero-forcing (ZF), layered virtual signal-to-interfere
Correlation coefficient, as a critical performance metric of multiple antenna systems, can be calculated from the 3D radiation patterns of the antennas for multipath environments with uniform 3D angular power spectrum. A simpler, faster and lower cost approach uses the antennas’ scattering parameters to determine correlation coefficient. However, the method assumes lossless antennas, and hence onl
The design of multiple antennas in compact mobile terminals is a significant challenge, due to both practical and fundamental design tradeoffs. In this paper, fundamental antenna design tradeoffs of multiple antenna terminals are presented in the framework of characteristic mode analysis. In particular, interactions between the antenna elements and the characteristic modes and their impact on desi
Seven aliphatic dicarboxylic acids (C3-C9) along with phthalic acid, pinic acid and pinonic acid were determined in 35 aerosol (PM10) samples collected over the year at Vavihill sampling station in south of Sweden. Mixture of dichloromethane and methanol (ratio 1:3) was preferred over water for extraction of samples and extraction was assisted by ultrasonic agitation. Analytes were derivatized usi
Despite its long history, the Theory of Characteristic Modes has only been utilized in antenna design for perfect electric conductors. This is due to computational problems associated with dielectrics and magnetic materials. In particular, the symmetric form of the PMCHWT surface formulation for the Method of Moments (MoM) solves for both external (real) and internal (non-real) resonances of a str
Compact arrays such as multiple antennas on a mobile terminal suffer from low efficiency and high correlation between antenna signals. In the present paper, a simple and rigorous procedure for decoupling two closely coupled antennas with a parasitic scatterer is proposed. The parasitic scatterer, which can be an additional antenna, acts as a shield between two active antenna elements. In contrast
We study the potential benefits of cooperative multiple-input multiple-output signaling from multiple coherent base stations with one or more mobile stations in an urban macrocellular environment at 2.66 GHz. The analysis uses fully-coherent measurements of the channel from three base stations to a single mobile station equipped with four antennas. The observed channels are used to explore the gai
The pervasive use and insatiable demand for high-performance wireless devices globally are driving the development of new communication technologies and standards. In this chapter, we present advancements in the area of terminal antenna systems and describe how they play a major role in enabling strict performance requirements to be met in future systems. As opposed to conventional systems that do
An increasing demand from e.g. real-time multimedia applications (IPTV, OTT) adds strains on especially DSL based access links. In this paper we argue why it is important to study DSL link impairments and their impact on QoS parameters on higher layers. We discuss the need for establishing methods for quality of service estimation with cross layer techniques and present some initial results.
Pattern reconfigurability is a desirable feature of mobile handset antennas, as it enables the antennas to adapt to non-stationary propagation environments. However, it is difficult to vary the radiation pattern of a handset antenna at frequencies below 1 GHz because the entire chassis commonly acts as the main radiator. Hence, designing pattern reconfigurability based on the antenna element (seco
We present a comparative exploratory analysis of two proximity networks of mobile phone users, the Proximates network and the Reality Mining network. Data for both networks were collected from mobile phones carried by two groups of users. Periodic Bluetooth scans were performed to detect the proximity of other mobile phones. The Reality Mining project took place in 2004-2005 at MIT, while Proximat
Random-walk and diffusion models for two-choice comparison of paired successive or simultaneous stimuli focus on response time (RT), modeled as the time needed to reach one or the other barrier, and its relation to the response probabilities. Logit P1 = ln[P1/(1-P1)], where P1 is the probability of responding ”first greater,” can be seen as a measure of subjective stimulus difference, d. Signed re
Many full-reference objective metrics require that the original and the degraded video contain the same number of frames. Most codecs are not able to decode the video properly when the video is subject to packet losses and produce incomplete video files with lower number of frames than the original video. In this paper we present a simple method to reconstruct the degraded videos so that it has th
