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Based on static outdoor channel measurements we evaluate the influence of a vehicle on the MIMO radio channel, from a base station antenna array, to a multiple antenna handset in the hand of a user placed inside a test car. The measurement scenario is chosen to mimic a 2.6 GHz (LTE) macro-cell urban or rural scenario with two locations and orientations of the car, one at an open parking lot with a
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
Traffic measurements in broadband access networks are crucial from several points of view. A better understanding of traffic patterns can lead to more efficient network design, which leads to energy and cost savings for the operator and improved end user services. This paper reports on selected traffic measurement results from the Celtic TRAMMS project. The measurements were performed in broadband
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
It has been proposed that six co-located antennas, namely three electric and three magnetic dipoles, can offer up to a six-fold capacity increase in wireless channels, relative to that of single antennas. In other words, six degrees of freedom (DOFs) can be supported by co-located six-port transmit and receive antenna arrays. However, due to the complexity in designing and measuring such a six-por
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
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
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
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 practical risk analysis method for critical, large-scale IT systems in an organisation. The method is based on reliability block diagram modelling and was adapted to fit the requirements of governmental organisations and to reduce the effort required to capture complex failure behaviour. Through the use of different failure categories the risk analysis can be simplified, the
In FSE 2010, Rønjom and Cid put forward a nonlinear equivalence for Boolean functions and demonstrated that many cryptographic properties are not invariant among functions within the same equivalence class by providing some special examples. Their paper presented the idea and many problems were left open.In this paper, we investigate equivalence of Boolean functions more deeply using a new method
The decoding problem is a fundamental problem in computational complexity theory. In particular, the efficiency of which the problem can be decided has implications on the security of cryptosystems based on hard problems in coding theory. Stern's algorithm has long been the best algorithm available, with slight modifications over the years yielding only small speed-ups. This paper describes an imp
