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Massive multiple-input multiple-out (MIMO) is vital in millimeter-wave (mmWave) bands to obtain large array gains. However, there are practical challenges, such as high hardware cost and power consumption in such systems. A promising solution to these problems is to adopt a hybrid beamforming architecture. This architecture has a much lower number of transceiver (TRx) chains than the total antenna
Context:: Software-intensive organizations’ rationale for sharing Open Source Software (OSS) may be driven by both idealistic, strategic and commercial objectives, and include both monetary as well as non-monetary benefits. To gain the potential benefits, an organization may need to consider what they share and how, while taking into account risks, costs and other complexities. Objective:: This st
Evidence-based software engineering (EBSE) aims to improve research utilization in practice. It relies on systematic methods (like systematic literature reviews, systematic mapping studies, and rapid reviews) to identify, appraise, and synthesize existing research findings to answer questions of interest. However, the lack of practitioners' involvement in the design, execution, and reporting of th
Background:Joint research between industry and academia benefits both communities.For researchers, working with practitioners, it is a chance to collect empirical data and test research-based solution proposals.For practitioners, one of the main benefits is access to scientific knowledge.Despite the benefits, there is a gap between industry and academia that could be addressed through more joint r
Hidden antenna solutions for car roofs are of current interest to car manufacturers, to avoid having larger shark-fin based antenna systems to support growing number of wireless services. However, there are only a few studies in the literature on the integration of hidden antennas, particularly in relation to realistic roofs and propagation channels. This paper investigates the performance impact
The Theory of Characteristic Modes (TCM) offers a natural and systematic way to design Multiple-Input Multiple-Output (MIMO) antennas with high total efficiency and uncorrelated antenna patterns. In this paper, recent advances in the growing field of TCM-aided MIMO antenna design are reviewed. In particular, the focus is on the challenging problem of designing MIMO antennas for compact mobile term
The quantification and characterization of circulating immune cells provide key indicators of human health and disease. To identify the relative effects of environmental and genetic factors on variation in the parameters of innate and adaptive immune cells in homeostatic conditions, we combined standardized flow cytometry of blood leukocytes and genome-wide DNA genotyping of 1,000 healthy, unrelat
In this paper, we study random puncturing of protograph-based spatially coupled low-density parity-check (SC- LDPC) code ensembles. We show that, with respect to iterative decoding threshold, the strength and suitability of an LDPC code ensemble for random puncturing over the binary erasure channel (BEC) is completely determined by a single constant that depends only on the rate and iterative deco
This work focuses on the design of SC-LDPC codes for transmission over non-ergodic, block-fading channels. Our main contribution is an algorithm, allowing to start from a (J,K )-regular, uncoupled LDPC ensemble, from which one can recursively build up a protograph-based SC-LDPC ensemble having any target diversity order d. The diversity order is achieved assuming a low-complexity iterative decodin
Background: There is a need for ecient regression testing in most software development organizations. Often the proposed solutions involve automation. However, despite this being a well researched area, research results are rarely applied in industrial practice. Aim: In this paper we aim to bridge the gap between research and practice by providing examples of how evidence-based regression testing
In this work we present a new low-power medium access scheme for sensor-type networks specifically with low traffic intensity. We call the proposed scheme DCW-MAC where ultra-low-power wake-up receivers are combined with optimal duty-cycled listening. First we introduce a framework for the analysis of energy consumption of the studied network type, then we use it to optimize the MAC scheme to achi
Requirements Engineering and Testing are considered inseparable and together enable successful projects. One could make a statement that serious negligence of any of the two will bring catastrophic consequences for the project, delays, failures and unhappy customers. Thus, alignment and cooperation between the two are not only recommended but highly required for contemporary complex software and s
This paper describes an extensive propagation channel measurement campaign in a warehouse environment for line-of-sight (LOS) and nonline-of-sight (NLOS) scenarios. The measurement setup employs a vector network analyzer operating in the 2-8-GHz frequency band combined with an 8×8 virtual multiple-input multiple-output (MIMO) antenna array. We develop a comprehensive statistical propagation channe
We investigate antenna correlation of an M-antenna massive multiple-input multiple-output (MIMO) setup with the purpose of obtaining a low-rank representation of the instantaneous massive MIMO channel. Low-rank representation bases using short-term and long-term antenna correlation statistics are defined, and their performance is evaluated with data sets obtained from channel measurements in both
Coordinated Multi Point (CoMP) transmission and reception techniques are used in order to improve the performance of single or multiple cells in wireless systems. A system using CoMP techniques is capable of jointly optimizing its transmission and/or reception and, hence, achieving higher performance. In this work, performance evaluation of three CoMP techniques are performed based on simulations
The possibility of using radio over fiber (RoF) analog transmissions to characterize the wireless propagation channel of distributed antenna systems is investigated. In particular, the coherence time of kilometer-long, fiber-based networks is analyzed. Joint measurements of the phase noise of parallel links to the same site (intra-site) and to different sites (inter-site) in such a network are pre
A fully integrated remote antenna unit (RAU) intended for fiber-fed distributed multiple-input multiple-output systems is presented. The circuit is designed for narrowband (60 MHz) time-division duplex systems, where an IF over fiber approach is chosen to facilitate the use of low-cost optical components and integrated photodetectors. A novel antenna switch control scheme is introduced, which enab
Massive MIMO is a promising technology for the coming 5G wireless systems. In this paper, a programmable baseband processor specifically designed for uplink symbol detection targeting massive MIMO is presented with a novel matrix inversion method proposed to obtain more precise and efficient computation. Including a microcode controlled channel preprocessing unit and a pipelined detection unit, th
This paper serves as an overview to the special session Circuits and Systems for 5G on IEEE International Conference on ASIC (ASICON) 2015. More specifically, we introduce two of enabling technologies for the coming 5G wireless era, namely massive multiple-input multiple-output (MIMO) technique and advanced coding techniques such as polar codes. Massive MIMO is a relatively new wireless communicat
