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Directional antennas have been used to solve interference and connectivity issues in wireless networks for some time. Many scenarios have been presented and often positive conclusions are drawn, i.e., showing the increase in capacity. However, to date the research has mainly focused on either antenna placement or transmission scheduling but not the two combined. Such consideration will become incr
This paper presents an analysis on energy dissipation of digital half-band filters operating in the sub-threshold (sub-VT) region with throughput and supply voltage constraints. A 12-bit filter is implemented along with various unfolded structures, used to form a decimation filter chain. The designs are synthesized in a 65 nm low-leakage CMOS technology with various threshold voltages. A sub-VT en
From our experimental investigation of multiple-antenna performance and user impact of a realistic mobile terminal setup, we find that apart from the important loss of efficiency due to the user hand, the impact on the individual antennna elements and the directional impact of the user body shadowing have quite small influence on the diversity and capacity performance. It is found that the top and
Abstract in UndeterminedVehicular communication channels are characterized by a nonstationary time-frequency-selective fading process due to rapid changes in the environment. The nonstationary fading process can be characterized by assuming local stationarity for a region with finite extent in time and frequency. For this finite region, the wide-sense stationarity and uncorrelated scattering assum
This paper presents a flexible architecture suitable for performing both channel estimation and signal detection in a MIMO-OFDM downlink. Extensive hardware sharing between two tasks is achieved by algorithm and architecture co-design, where robust MMSE sliding window channel estimation and MMSE-based signal detection with symbol perturbation scheme are adopted. The proposed architecture is based
The IDEM3 maturity model is a process improvement framework that can be used by an organisation to assess and improve their IT dependability management processes. The framework focuses on the coordination of IT management and safety management within an organisation. In this paper, an evaluation plan for the maturity model is presented to evaluate its applicability, assessment accuracy, and practi
Abstract in UndeterminedWe introduce a new method for prestack depth migration of seismic common-shot gathers.The computational procedure follows standard steps of the reverse-time migration, i.e.,downward continuation of the `source' and the `receiver' waveelds, followed by applicationof an imaging condition (e.g. zero-lag cross-correlation of these elds). In our method werst nd a sparse data rep
Manual software testing is a widely practiced verification and validation method that is unlikely to fade away despite the advances in test automation. In the domain of manual testing, many practitioners advocate exploratory testing (ET), i.e., creative, experience-based testing without predesigned test cases, and they claim that it is more efficient than testing with detailed test cases. This pap
The theoretical phase noise performance of a tuned-input tuned-output (TITO) oscillator is analyzed with a rigorous approach, which yields a compact closed-form phase noise equation that is dependent only on the value of the circuit components and current consumption of the oscillator. A straightforward comparison with the more commonly used differential LC-tank oscillator shows that the latter is
Aim: Regression testing practices in industry have to be better understood, both for the industry itself and for the research community. Method: We conducted a qualitative industry survey by i) running a focus group meeting with 15 industry participants and ii) validating the outcome in an on line questionnaire with 32 respondents. Results: Regression testing needs and practices vary greatly betwe
Capacity improvement of intrasite cooperative MIMO using all three 120 degree-sectors of a base station (BS) site is studied for the first time in a measured urban environment at 2.65GHz. The results show that the mean uplink capacity gain exceeds 40% in as much as 1/4 of the coverage area, relative to the best single-sector link with no cooperation. In addition, a simple simulation model is devel
Large open and closed source organizations like Google, Facebook and Mozilla are migrating their products towards rapid releases. While this allows faster time-to-market and user f eedback, it also implies less time for testing and bug fixing. Since initial research results indeed show that rapid releases fix proportionally less reported bugs than traditional releases, this paper investigates the
Computing is no longer considered a subject area only relevant for a narrow group of professionals, but rather as a vital part of general education that should be available to all children and youth. Since making changes to national curricula takes time, people are trying to find other ways of introducing children and youth to computing. In Sweden, several current initiatives by researchers and te
Input data for communication network design/optimization problems involving multi-hour or uncertain traffic can consist of a large set of traffic matrices. These matrices are explicitly considered in problem formulations for link dimensioning. However, many of these matrices are usually dominated by others so only a relatively small subset of matrices would be sufficient to obtain proper link capa
In this paper we propose a new algorithm for solving the Learning With Errors (LWE) problem based on the steps of the famous Blum-Kalai-Wasserman (BKW) algorithm. The new idea is to introduce an additional procedure of mapping subvectors into codewords of a lattice code, thereby increasing the amount of positions that can be cancelled in each BKW step. The procedure introduces an additional noise
Abstract in UndeterminedWe introduce Gaussian wave packets in pursuit of representations of functions, in which the representation is invariant under translation, modulation, scale,rotation and anisotropic dilation. Properties of both continuous and discrete representations are discussed. For the discrete (two-dimensional) case, we develop fastalgorithms for the application of the analysis and syn
