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Background: The fix-cache approach to regression test selection was proposed to identify the most fault-prone files and corresponding test cases through analysis of fixed defect reports. Aim: The study aims at evaluating the efficiency of this approach, compared to the previous regression test selection strategy in a major corporation, developing embedded systems. Method: We launched a post-hoc
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
The traditional routing protocols used in wireless mesh networks like AODV are not very efficient since the number of hops to a destination is mainly considered as the routing metric. This may lead to shorter paths; however, the throughput can decrease when traffic is routed through those paths. Various contributions have proposed different metrics or completely different routing algorithms. Never
Spatially coupled regular LDPC code ensembles have outstanding performance with belief propagation decoding and can perform close to the Shannon limit. In this paper we investigate the suitability of coupled regular LDPC code ensembles with respect to rate-flexibility. Regular ensembles with good performance and low complexity exist for a variety of specific code rates. On the other hand it can be
In this paper we evaluate the use of parallel interleavers for user separation in coded IDMA systems. The parallel interleavers have previously been evaluated for uncoded systems, and we here present extended results for the coded case. The new results are important for real systems, as they will most likely use performance enhancing channel coding. The parallel interleavers are designed to remove
Context: Systems of systems (SoS) are highly complex and are integrated on multiple levels (unit, component, system, system of systems). Many of the characteristics of SoS (such as operational and managerial independence, integration of system into system of systems, SoS comprised of complex systems) make their development and testing challenging. Contribution: This paper provides an understanding
An all digital phase-locked loop (ADPLL) has been implemented in a 90-nm CMOS process. It uses a phase-frequency detector (PFD) connected to two time-to-digital converters (TDC). To save power the TDCs use delay line cells with uneven delay time. During frequency acquisition an automatic tuning bank controller selects active bank of the digitally controlled oscillator (DCO), which features three s
MIMO systems ideally achieve linear capacity gain proportional to the number of antennas. However, the compactness of terminal devices limits the number of spatial degrees of freedom (DOFs) in such systems, which motivates efficientantenna design techniques to exploit all available DOFs. In this contribution, we present a compact six-port dielectric resonator antenna (DRA) array which utilizes spa
Open source software has been gaining popularity, especially among commercial organizations. The broad industry acceptance is in large part due to the demonstrated ability of open source solutions to compete with proprietary alternatives. Using open source software components enables companies to reduce their own development costs, and thus improve software development efficiency. Many open source
This paper presents a 2.45 GHz wake-up receiver front-end intended for use in sensor networks, and is designed to receive data modulated with on-off-keying. Manufactured in 65 nm CMOS it employs an uncertain IF structure with three phase passive mixer and high gain amplifier chain. With the modulation frequency response tailored to the detector behaviour, it achieves a sensitivity of -88 dBm at BE
Despite recent attempts to relax the phase-noise demands on voltage-controlled oscillators (VCOs) for cellular communications [1], mainstream radios require harmonic VCOs capable of a very low phase noise with moderate power consumption, associated to a large tuning range (TR) and a high insensitivity to interfering signals. Ideally, the TR should be in excess of one octave, since this allows the
In this paper, a novel multiple representation data structure for dynamic visualisation of 3D city models, called CityTree, is proposed. To create a CityTree, the ground plans of the buildings are generated and simplified. Then, the buildings are divided into clusters by the road network and one CityTree is created for each cluster. The leaf nodes of the CityTree represent the original 3D objects
The analysis and design of a millimeter-wave passive balun on silicon substrate with small size and good balance is presented. The reason for the imbalance of the balun is analyzed and a novel method using two grounded T bars beneath the coupled lines to tune the balance is proposed. The balun was fabricated in a 65 nm CMOS process, by using broadside coupled lines with small separation, the lengt
As a part of the LDTA 2011 Tool Challenge, we implemented a compiler for the language Oberon-0 using the metacompilation tool JastAdd. In this paper, we report on this implementation, and reflect on aspects of it such as ease of use, modularity, and safety.
We consider detection over intersymbol interference channels that are unknown at the receiver. For such a kind of systems, we consider an alternative approach to the design of a reduced-complexity receiver based on channel shortening without the explicit estimation of the channel impulse response. The proposed solution allows a simplification of the receiver architecture and a faster convergence f
Using the metric of channel capacity, three dual-antenna multiple-input multiple-output (MIMO) terminals with adaptive impedance matching were evaluated at LTE Band 13 in four different user scenarios using simulation. Each of the three terminals is equipped with a slot-monopole antenna and a planar inverted-F antenna (PIFA). The slot monopole is fixed at one edge of the chassis, whereas the locat
This paper presents a decoder for multi-carrier modulated signals employing Faster-than-Nyquist (FTN) signaling. FTN signaling is a method of improving bandwidth efficiency at the expense of higher processing complexity in the transceiver. The decoder can switch between orthogonal and FTN signaling modes and exploits channel properties to improve bandwidth efficiency. The decoder is fabricated in
In the paper we consider a commonly known network design problem with demand restoration assuming stub release. No compact linear programming (LP) formulation for the problem is known, and all known non-compact LP formulations of the problem require NP-hard path generation (pricing). Therefore, the problem itself is suspected to be NP-hard - this, however, is not actually known. The main result of
