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A complete architecture with transistor level simulation is presented for a low power analog convolutional decoder in 65 nm CMOS. The decoder core operates in the weak inversion (sub-VT) and realizes the BCJR decoding algorithm corresponding to the 4-state tail-biting trellis of a (7,5) convolutional code. The complete decoder also incorporates serial I/O digital interfaces and current mode differ

Fully-synchronous measurements of a massive multi-user multiple-input multiple-output (MU-MIMO) radio propagation channel are presented. We evaluate the ability of a massive MIMO system to spatially separate users located close to each other in line-of-sight (LOS) propagation conditions. The system consists of a base-station (BS) antenna array equipped with 64 dual-polarized antenna elements (128

In this paper, we present a new topology to implement a passive 180° phase shifter using on-chip auto-transformer in an SOS process. The measured results indicate a phase variation of less than 2° over the frequency range of 1.8-2.4GHz. An insertion loss of 2.3dB was measured at 2.1GHz. The phase shifter has a small footprint of 0.3 × 0.7mm2, which is almost three times less than a traditional hig

Indoor positioning is recognized as one of the upcoming major applications which can be used in wide variety of applications such as indoor navigation and enterprise asset tracking. The significance of localization in indoor environments have made the use of Wi-Fi based indoor positioning so that it can utilize available current wireless infrastructure and perform positioning very easily. In this

Software developers in large projects work in complex information landscapes, and staying on top of all relevant software artifacts is challenging. As software systems often evolve for years, a high number of issue reports is typically managed during the lifetime of a system. Efficient management of incoming issue requires successful navigation of the information landscape. In our work, we address

Spatially coupled low-density parity-check (SC-LDPC) codes are considered for transmission over the block-fading channel. The diversity order of the SC-LDPC codes is studied using density evolution and simulation results. We demonstrate that the diversity order of the code can be increased, without lowering the code rate, by simply increasing the coupling parameter (memory) of a SC-LDPC code. For

Vehicle-to-Vehicle (V2V) communication is an en-abler for improved traffic safety and congestion control. As for any wireless system the ultimate performance limit is determined by the propagation channel. A particular point of interest is the shadowing effect of large vehicles such as trucks and buses, as this might affect the communication range significantly. In this paper we present measuremen

We give a procedure to find good convolutional codes for use with iterative decoding (turbo equalization) of the coded AWGN intersymbol interference (ISI) channel. The method is based on the input-output bit error rate characteristic of the convolutional BCJR module in the iterative decoder, in combination with the code minimum distance. Both are essential to find best codes. Best feedforward and

Communication is essential for software development as its efficiency throughout the entire project life-cycle is a key factor in developing and releasing successful software products to the market. This paper reports on findings from an explanatory case study aiming at a deeper understanding of the causes and effects of communication gaps in a large-scale industrial set up. Based on an assumption

This paper presents a highly linear radio frequency receiver front-end with on-chip balun for cellular application at 2GHz in 65nm CMOS technology. Based on direct conversion architecture, the implemented front-end comprises a customized on-chip balun for single-ended to differential signal conversion, a differential common-gate low noise amplifier and voltage mode quadrature passive mixer. The si

We have previously shown how it is possible to lower accident risk levels while at the same time increasing traffic flows with the aid of vehicular ad-hoc networks. In this paper, we extend the online traffic accident risk mitigation sys- tem to include link choice. We develop an algorithm that allows vehicles to choose road links that provide the current maximal utility, based on information rece

Coordinating a software project across distances is challenging. Even without geographical and time zone distances, other distances within a project can cause communication gaps. For example, organisational and cognitive distances between product owners and development-near roles such as developers and testers can lead to weak alignment of the software and the business requirements. Applying good

We have implemented a prototype editor for a visual language where the semantics depends on layout. A high-level abstract syntax is defined, where these semantics can be captured without the need for storing concrete graphical coordinates. The model implementation is done in JastAdd, a metacompilation tool based on reference attribute grammars. This gives a modular architecture where the core comp

Abstract in Undetermined The 60 GHz band is very prominsing for high data rate (>1 Gb/s) wireless systems operating at short ranges. However, due to the short wavelengths in this frequency band, the shadowing effects cuased by human bodies and furniture are severe and needs to be modeled properly. In this paper, we present an experimental, measurement-based characterization of the reflection and s

Synthesis of case studies is different from synthesis of purely quantitative studies, for example, in that sampling and analysis in primary studies have been carried out differently, and that primary results are of a different nature. The objective of this research is to identify what challenges should be considered when choosing and using a method for synthesis of case studies. We collected exper

When a mobile station moves along a trajectory, it will see different parts of the same scatterers or scatterer groups during its movement. In this paper, we present a new method to identify such physical clusters of scatterers, and the corresponding groups of multipath components (MPCs) interacting with those clusters, from measurements of channel impulse responses. The method is based on identif

Abstract in UndeterminedVery large MIMO is a technique that potentially can offer large network capacities in multi-user scenarios where the users are equipped only with single antennas. In this paper we are investigating channel properties for a realistic, though somewhat extreme, outdoor base station scenario using a large array. We present measurement results using a 128 element linear array ba