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The COST 2100 channel model has introduced the concept of common clusters to model multi-link MIMO characteristics. In this paper, a ray launching tool is used to analyze multi-ink propagation properties in an outdoor scenario at 300 MHz. It is shown that in a multi-link propagation scenario there are shared scatterers among the different links, which reflects the physical existence of common clus
This article discusses opportunities and challenges of physical layer security integration in MaMIMO systems. Specifically, we first show that MaMIMO itself is robust against passive eavesdropping attacks. We then review a pilot contamination scheme that actively attacks the channel estimation process. This pilot contamination attack not only dramatically reduces the achievable secrecy capacity bu
Context: This paper analyses a sub-contractor specification in the mobile handset domain. Objective: The objective is to understand how quality requirements are specified and which types of requirements exist in a requirements specification from industry. Method: The case study is performed in the mobile handset domain, where a requirements specification was analyzed by categorizing and characteri
Geometry-based stochastic channel models (GSCMs) are extended to support multi-link simulations by applying the concept of common clusters. This novel approach aims to control the correlation between different links, inter-link correlation, by adjusting the amount of power simultaneously propagating via the same clusters in the different links. The behavior of common clusters is analyzed based on
This paper presents two class-C CMOS VCOs with a dynamic bias of the core transistors, which maximizes the oscillation amplitude without compromising the robustness of the oscillation start-up, thereby breaking the most severe trade-off in the original class-C topology. An analysis of several different oscillators, starting with the common class-B architecture and arriving to the proposed class-C
This paper presents a low band antenna impedance tuner in 130nm CMOS-SOI technology. It consists of three digitally controlled switched capacitor banks and two off-chip inductors and is intended for use in terminals supporting modern cellular standards like WCDMA and LTE. By using a negative gate bias in the off state, linearity can be improved and maintained. Measurements show an OIP3 exceeding +
In this paper we analyze the small-scale fading statistics for vehicle-to-vehicle (V2V) communications in a typical open sub-urban street crossing. The two cars approach the crossing from two different streets and the channel conditions vary from non line-of sight (NLOS) to line-of-sight (LOS). The small-scale fading of the first delay bin is Ricean distributed with a time-varying K-factor. The la
Abstract in UndeterminedAs standards and regulatory codes are issued by third party organizations and committees, the project organization can neither control the content of all standards that the projects should adhere to, nor negotiate or make changes to them that can make the project development easier. Moreover, large infrastructure projects require compliance with hundreds of standards of reg
Under början av förra seklet skedde en formlig reception av tysk processrätt genom Ernst Kallenbergs verk Svensk Civilprocessrätt i två band. Således kom läran om processföremålet genom 1942 års processreform att läggas till grund för utformningen av den svenska rättegångsbalken (RB). Läran om processföremålet innebär att saken är den omtvistade rättigheten i det bakom-liggande rättsförhållande soAt the turn of the last century, a formal reception of German procedural law took place through Ernst Kallenberg’s work ’Svensk Civilprocessrätt’ in two volumes. Thereby, the German doctrine on the essence of the claim formed the basis for the Swedish Code of Procedure, rättegångsbalken (RB), through the procedural reform of 1942. The doctrine on the essence of the claim holds that the matter cont
Could maintainability requirements help organizations prioritize technical debt management? The new standard ISO/IEC 5055 Automated Source Code Quality Measures can be used to set targets. We also look at a pragmatic way to turn CodeScene’s code health metric into a quality gate for pull requests.
As a general-purpose technology, large language models promise to enhance various software engineering tasks. But how will they impact requirements engineering? This column offers a summary of an expert panel discussion from the 2023 International Requirements Engineering Conference in Hanover, Germany.
Multi-user MIMO offers big advantages over conventional point-to-point MIMO: it works with cheap single-antenna terminals, a rich scattering environment is not required, and resource allocation is simplified because every active terminal utilizes all of the time-frequency bins. However, multi-user MIMO, as originally envisioned, with roughly equal numbers of service antennas and terminals and freq
Background: Currently available biomarkers for the early tissue process leading to joint damage in rheumatoid arthritis are insufficient and lack prognostic accuracy, possibly a result of variable activity of the disease over time. This study represents a novel approach to detect an altered activity of the disease process detected as increasing serum-COMP levels over a short time and whether this
This paper presents a noise cancelling 0.7– 3.8GHz receiver front-end implemented in 65nm technology. The circuit has a main path consisting of a high input impedance gm-stage, current-mode passive mixers and baseband amplifiers, where the input match is provided by frequency translational negative feedback from baseband to RF input. An auxiliary path with tunable gain is introduced to cancel nois
We compare the technique of using the orbital angular momentum (OAM) of radio waves for generating multiple channels in a radio communication scenario with traditional multiple-in-multiple-out (MIMO) communication methods. We demonstrate that, for certain array configurations in free space, traditional MIMO theory leads to eigen-modes identical to the OAM states. From this we conclude that communi
Unit verification, including software inspections and unit tests, is usually the first code verification phase in the software development process. However, principles of unit verification are weakly explored, mostly due to the lack of data, since unit verification data are rarely systematically collected and only a few studies have been published with such data from industry. Therefore, we explor
Low-complex and low power non-coherent energy detector (ED) is interesting for low data rate impulse radio (IR) ultra wideband (UWB) systems but, compared to coherent receivers, it suffers from a loss in performance due to low signal-to-noise ratio (SNR) at the detector. In addition, the performance of an ED strongly depends on the integration interval (window size) of the integrator and the window
