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The design of antennas for compact multiple-input multiple-output (MIMO) terminals is a challenging feat, due to the space constraint and the physical structure of the terminal. The space constraint forces the antennas to be closely spaced, which degrades MIMO performance due to high signal correlation and low antenna efficiency. Moreover, the terminals are equipped with ground planes which furthe
For multiple antennas on a compact terminal chassis, chassis current excitation can severely increase mutual coupling between the antennas. This is because the same characteristic mode of the chassis may be strongly excited by more than one antenna. Here, we propose to use one antenna that exploits chassis excitation and introduce a second antenna that minimizes chassis excitation. In this way, an
The compactness of mobile terminals complicates the design of multiple antennas, since coupling among the antennas increases when they are placed in proximity of one another. While it is possible to mitigate coupling between closely spaced antennas, a tradeoff in bandwidth is required. In this paper, we highlight ground plane excitation as an additional dimension to consider in the design of multi
Traditionally, doctoral education is designed to train students to become skilled researchers in their respective disciplines. In many cases, however, doctoral graduates find themselves ill-prepared for their career choices. In this paper, we adopt a systematic approach to study the career preparation aspect of doctoral study in our home department. Our findings reveal several shortcomings in the
A system for local oscillator (LO) signal generation in 5G millimeter-wave (mmW) multi-antenna transceivers is presented. The system is modular with one phase locked loop (PLL) per antenna element transceiver, and a test circuit implemented in 28-nm fully depleted silicon on insulator (FD-SOI) CMOS features two such PLLs and a 491.52 MHz crystal oscillator (XO) generating a common frequency refere
This paper demonstrates multiple-input-multiple-output (MIMO) throughput performance of a six-port dielectric resonator antenna (DRA) array for Wireless-LAN applications in a measured indoor office environment when a six-port dual-polarized patch array is used at the transmitter. The throughput was obtained using an IEEE802.11n/Draft 5.00 simulator for measured channels with different antenna and
In this paper, we study the potential benefits of downlink cooperative MIMO systems in cellular macrocell environments using a coherent measurement setup. Our results reveal that one of the two measured routes can leverage comparable signal strengths from the cooperating base stations to the mobile station and provide up to two-fold single user bitrate gain at the 50% cumulative probability level
With the emergence of industrial IoT and cloud computing, and the advent of 5G and edge clouds, there are ambitious expectations on elasticity, economies of scale, and fast time to market for demanding use cases in the next generation of ICT networks. Responsiveness and reliability of wireless communication links and services in the cloud are set to improve significantly as the concept of edge clo
We assume that an intuitive means for the specification, re-use, modification and transfer of synchronized motions-both regarding the two arms of a dual-arm robotic system, as well as regarding the coordination of a user and a robot-is key in interactive and collaborative settings as they are currently targeted for industrial applications. We show, how our knowledge based approach to end-user prog
Many ships today rely on Global Navigation Satellite System (GNSS), for their navigation, where GPS (Global Positioning System) is the most well known. Unfortunately, the GNSS systems make the ships dependent on external systems, which can be malfunctioning, be jammed or be spoofed. There are today some proposed techniques where, e.g. bottom depth measurements are compared with known maps using Ba
Dealing with missing data in data analysis is inevitable. Although powerful imputation methods that address this problem exist, there is still much room for improvement. In this study, we examined single imputation based on deep autoencoders, motivated by the apparent success of deep learning to efficiently extract useful dataset features. We have developed a consistent framework for both training
Rapporten sammanfattar fjärilsinventeringar utförda 2016 inom Biogeografisk uppföljningsom drivs av Naturvårdsverket. I fjällområdet kunde 66 ytor inventeras och sammanlagtnoterades 80 högnordiska blåvingar på 20 ytor och 55 dvärgpärlemorfjärilar på 19 ytor.Inventeringen gav dessvärre inget fynd av fjällsilversmygare detta år. Förekomsten avtajgafjällfly undersöktes på 8 lokaler från Lycksele lapp
The digital cellular systems era started about thirty years ago with the release of the first digital cellphones. These first digital cellphones were very different from today’s slim and esthetic cellular pocket computers. They were not mass-produced in million units a day, and they were designed for radio performance rather than appearance. Today, all components are integrated inside the mobile p
[Context] Accurate time estimation is a critical aspect of predictable software engineering. Previous work shows that low source code quality increases the uncertainty in issue resolution times. [Objective] Our goal is to evaluate how developers' project experience and file ownership are related to issue resolution times. [Method] We mine 40 proprietary software repositories and conduct an observa
Background: The software engineering community has expressed growing concern regarding the need for more connections between research and practice. Despite the large amount of knowledge researchers generate, its impact on real-world practice is uncertain. Meanwhile, practitioners in industry often struggle to access and utilize relevant research outcomes that could inform and enhance their work. C
Most recent programming languages, such as Java, Python and Ruby, include a collection framework as part of their standard library (or runtime). The Java Collection Framework provides a number of collection classes, some of which implement the same abstract data type, making them interchangeable. Developers can therefore choose between several functionally equivalent options. Since collections hav
This special section of the IEEE OPEN JOURNAL OF CIRCUITS AND SYSTEMS (OJCAS) is dedicated to highlight the state-of-the-art research progress on circuits, systems, and algorithms associated with the design of beyond 5G (B5G) and 6G wireless systems.
CC-GLPDC codes are a class of generalized low-density parity-check (GLDPC) codes where the constraint nodes (CNs) represent convolutional codes. This allows for efficient decoding in the trellis with the forward-backward algorithm, and the strength of the component codes easily can be controlled by the encoder memory without changing the graph structure. In this letter, we extend the class of CC-G
Introduction Knee muscles are commonly labeled as flexors or extensors and aptly stabilize the knee against sagittal plane loads. However, how these muscles stabilize the knee against adduction-abduction and rotational loads remains unclear. Our study sought 1) to classify muscle roles as they relate to joint stability by quantifying the relationship between individual muscle activation patterns a
