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Massive MIMO enables a very high spectral efficiency by spatial multiplexing and opens opportunities to reduce transmit power per antenna. On the other side, it also introduces new challenges in tackling the power amplifier nonlinearity due to the increased number of antennas. The behavior of Out-of-Band radiation from PAs in Massive MIMO is non-trivial depending upon the applied precoding scheme,

Context: Software development is moving towards a place where data about development is gathered in a systematic fashion in order to improve the practice, for example, in tuning of static code analysis. However, this kind of data gathering has so far primarily happened within organizations, which is unfortunate as it tends to favor larger organizations with more resources for maintenance of develo

Software systems are increasingly depending on data, particularly with the rising use of machine learning, and developers are looking for new sources of data. Open Data Ecosystems (ODE) is an emerging concept for data sharing under public licenses in software ecosystems, similar to Open Source Software (OSS). It has certain similarities to Open Government Data (OGD), where public agencies share da

Testing of autonomous vehicles involves enormous challenges for the automotive industry. The number of real-world driving scenarios is extremely large, and choosing effective test scenarios is essential, as well as combining simulated and real world testing. We present an industrial workbench of tools and workflows to generate efficient and effective test scenarios for active safety and autonomous

Software bugs cost time, money, and lives. They drive software research and development efforts, and are central to modern software engineering. Yet we lack a clear and general definition of what bugs are. Some bugs are defects, clearly defined as failures to meet some requirement or specification. However,there are many forms of undesirable program behaviour that are completely compatible with a

American bison (Bison bison L.) have recovered from the brink of extinction over the past century. Bison reintroduction creates multiple environmental benefits, but impacts on greenhouse gas emissions are poorly understood. Bison are thought to have produced some 2 Tg yr-1 of the estimated 9 15 Tg yr-1 of pre-industrial enteric methane emissions, but few measurements have been made due to their mo

This paper presents a fully integrated 60 GHz frontend for phased array receivers. For the first time in the literature a phase controlled phased locked loop (PC-PLL) is used for beamforming at 60 GHz. The front-end performs a two stage frequency down-conversion, first from 60 GHz to 20 GHz, then from 20 GHz to quadrature baseband. Both the local oscillator signals at 20 GHz and 40 GHz are generat

In market-driven product development, it is important that the software product is released to the market at the right time, and offers higher quality than the competitors. In release planning, the allocation of development effort in investments into product enhancements, functions are competing with quality requirements for limited resources. In addition, it is important to find the right balance

Decision-making is central to Software Product Management (SPM) and includes deciding on requirements priorities and the content of coming releases. Several algorithms for prioritization and release planning have been proposed, where humans with or without machine support enact a series of steps to produce a decision outcome. Instead of applying some specific algorithm to find an acceptable soluti

Reducing the complexity of decoding algorithms for LDPC codes is an important prerequisite for their practical implementation. In this work we propose a reduction of computational complexity targeting the highly reliable codeword bits and show that this approach can be seamlessly merged with the forced convergence scheme. We also show how the minimum achievable complexity of the resulting scheme f

Two branches of gated ring oscillators (GRO) act as the delay lines in 2-dimension Vernier time-to-digital converter (TDC). The proposed architecture reduces dramatically the inherent latency of vernier structure. The already small quantization noise of the standard Vernier TDC is further first-order shaped by the GRO operation. The TDC has been simulated in 90nm CMOS technology. Operating from 50

This paper presents a robust and low-complexity non-linearity suppression scheme for radio frequency (RF) transceiver building blocks to efficiently mitigate intermodulation distortion. The scheme consists of tunable RF components assisted by an auxiliary path equipped with an adaptive digital signal processing algorithm to provide the tuning control. This proposed concept of digitally-assisted tu

A variable gain transimpedance amplifier (TIA) is presented featuring single-ended to differential conversion by means of negative feedback. The proposed topology also ensures stability when amplifier gain is varied. Furthermore, effective input capacitance of the TIA is reduced by using a positive capacitive feedback. The circuit is intended for intermediate frequency (IF) over fiber systems, but

Background: The literature concerning research methodologies and methods has increased in software engineering in the last decade. However, there is limited guidance on selecting an appropriate research methodology for a given research study or project.Objective: Based on a selection of research methodologies suitable for software engineering research in collaboration between industry and academia

Background: The socio-technical characteristic of software engineering is acknowledged by many, while the technical side still dominates research. As software engineering is a human-intensive activity, the cognitive side of software engineering needs more exploration when trying to improve its efficiency.Aim: The aim of this study is to increase the understanding of the impact of cognitive load in

This paper documents the global climate model EC-Earth3-AerChem, one of the members of the EC-Earth3 family of models participating in the Coupled Model Intercomparison Project Phase 6 (CMIP6). EC-Earth3-AerChem has interactive aerosols and atmospheric chemistry and contributes to the Aerosols and Chemistry Model Intercomparison Project (AerChemMIP). In this paper, we give an overview of the model

While Bayesian Optimization (BO) is a very popular method for optimizing expensive black-box functions, it fails to leverage the experience of domain experts. This causes BO to waste function evaluations on bad design choices (e.g., machine learning hyperparameters) that the expert already knows to work poorly. To address this issue, we introduce Bayesian Optimization with a Prior for the Optimum

Large intelligent surface (LIS) is a technology that extends massive MIMO by considering an even greater number of antennas distributed throughout vast areas. In order to be able to implement this technology, it is crucial to consider decentralized architectures so as to make the whole system scalable. We consider a LIS divided into several LIS panels of smaller size, which can be located far away

In this paper, we combine practically verified results from circuit theory with communication-theoretic laws. As a result, we obtain closed-form theoretical expressions linking fundamental system design and environment parameters with the power consumption of analog front ends (AFEs) for communication receivers. This collection of scaling laws and bounds is meant to serve as a theoretical referenc