Qamcom Research and Technology AB

Göteborg, Sweden

Qamcom Research and Technology AB

Göteborg, Sweden
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Grant
Agency: European Commission | Branch: H2020 | Program: ECSEL-RIA | Phase: ECSEL-08-2015 | Award Amount: 11.60M | Year: 2016

SafeCOP (Safe Cooperating Cyber-Physical Systems using Wireless Communication) will establish a safety assurance approach, a platform architecture, and tools for cost-efficient and practical certification of cooperating cyber-physical systems (CO-CPS). SafeCOP targets safety-related CO-CPS characterized by use of wireless communication, multiple stakeholders, dynamic system definitions, and unpredictable operating environments. In this scenario, no single stakeholder has the overall responsibility over the resulted system-of-systems; safe cooperation relies on the wireless communication; and security and privacy are important concerns. Although such CO-CPS can successfully address several societal challenges, and can lead to new applications and new markets, their certification and development is not adequately addressed by existing practices. SafeCOP will provide an approach to the safety assurance of CO-CPS, enabling thus their certification and development. The project will define a platform architecture and will develop methods and tools, which will be used to produce safety assurance evidence needed to certify cooperative functions. SafeCOP will extend current wireless technologies to ensure safe and secure cooperation. SafeCOP will also contribute to new standards and regulations, by providing certification authorities and standardization committees with the scientifically validated solutions needed to craft effective standards extended to also address cooperation and system-of-systems issues. SafeCOP brings clear benefits in terms of cross-domain certification practice and implementations of cooperating systems in all addressed areas: automotive, maritime, healthcare and robotics. The advantages include lower certification costs, increased trustworthiness of wireless communication, better management of increasing complexity, reduced effort for verification and validation, lower total system costs, shorter time to market and increased market share.


Grant
Agency: European Commission | Branch: H2020 | Program: RIA | Phase: ICT-14-2014 | Award Amount: 8.17M | Year: 2015

The mmMAGIC (Millimetre-Wave Based Mobile Radio Access Network for Fifth Generation Integrated Communications) project will develop and design new concepts for mobile radio access technology (RAT) for mm-wave band deployment. This is envisaged as a key component in the 5G multi-RAT ecosystem and will be used as a foundation for global standardization. The project will thus enable ultrafast mobile broadband services for mobile users, supporting UHD/3D streaming, immersive applications and ultra-responsive cloud services. The consortium brings together major infrastructure vendors (Samsung, Ericsson, Alcatel-Lucent, Huawei, Intel, Nokia), major European operators (Orange, Telefonica), leading research institutes and universities (Fraunhofer HHI Institute, CEA-LETI, IMDEA Networks, Universities Aalto, Bristol, Chalmers and Dresden), measurement equipment vendors (Keysight Technologies, Rohde & Schwarz) and one SME (Qamcom). To complement its strong industry leadership and academic excellence, the project has an Advisory Board drawn from major European telecommunications regulators in Germany, France, Finland, Sweden and the UK. A new radio interface, including novel network management functions and architecture components will be proposed, taking as guidance 5G PPPs KPI and exploiting the use of novel adaptive and cooperative beam-forming and tracking techniques to address the specific challenges of mm-wave mobile propagation. The project will undertake extensive radio channel measurements in the 6-100 GHz range, and will develop and validate advanced channel models that will be used for rigorous validation and feasibility analysis of the proposed concepts and system, as well as for usage in regulatory and standards fora. The ambition of the project is to pave the way for a European head start in 5G standards, including 3GPP, and to secure essential IPRs to European industry, strengthening European competitiveness.


Chen X.,Qamcom Research and Technology AB | Kildal P.-S.,Chalmers University of Technology | Carlsson J.,SP Technical Research Institute of Sweden
IET Science, Measurement and Technology | Year: 2015

Measurements in reverberation chamber (RC) produce data that are random, and therefore they need to be processed from the statistical point-of-view for obtaining the desired characteristics and the accuracy. The complex channel transfer function in the RC follows complex Gaussian distribution provided that the RC is well stirred. The authors have recently presented a new uncertainty model based on the presence of an unstirred component of the transfer function, which was modelled by introducing an average Rician K-factor. The model was validated in two RCs with translating mode-stirring plates, being able to correctly describe the improvement in accuracy by rotating the antenna under test, and by blocking the line-of-sight between this and the fixed RC antenna(s). In the present study, they apply this uncertainty model to four RCs with different settings (e.g. RC volumes, number of plates or fixed RC antennas, translating and rotating mode-stirrers etc.). For each RC, they examine the measurement uncertainty under different loading conditions. To repeat (during the different measurements) the actual mode-stirrer positions at which the transfer function is sampled, they conduct all the measurements with stepwise (instead of continuous) modestirring. The model is shown to work well for all the cases. © The Institution of Engineering and Technology 2015.


Mello D.A.A.,University of Brasilia | Barreto A.N.,University of Brasilia | De Lima T.C.,University of Brasilia | Portela T.F.,University of Brasilia | And 3 more authors.
Journal of Lightwave Technology | Year: 2014

We evaluate the impact of variable-code-rate transceivers on cost, capacity and survivability of wavelength-routed optical networks. The transmission rate and reach trade-off is quantified for two hypothetical coded modulation schemes (aggressive and conservative) in a wavelength routing network with 50-GHz-spaced channels. The aggressive scenario assumes the 64-QAM modulation format, a small gap to capacity, and a small excess bandwidth. The conservative scenario considers the 16-QAM modulation format, and a larger capacity gap and excess bandwidth. The performance of the conservative and aggressive technologies is evaluated in three representative networks. Transparent reaches are calculated by means of an existing analytical method which assumes the AWGN hypothesis for the nonlinear noise. It is shown that variable-code-rate transceivers enable the concept of soft protection, in which the protection lightpath operates at a data rate which is lower than the corresponding working lightpath, in a way to avoid regeneration. This is specially attractive in the transport of IP traffic, where capacity reduction (in average up to 25%) may be tolerable during a repair time. It is also shown that variable-code-rate transceivers have the potential to offer significant savings in terms of transceiver usage and wavelength occupation, when compared to current fixed-rate transceivers operating at 100, 200 or 400 Gb/s. Finally, practical variable-code-rate transceivers may achieve a discrete set of $N$ code rates, yielding a quantized capacity-versus-reach curve. The system impact of $N$ is evaluated for several network scenarios. © 1983-2012 IEEE.


Beygi L.,Qamcom Research and Technology AB | Agrell E.,Stanford University
IEEE Signal Processing Magazine | Year: 2014

In this tutorial, we study the joint design of forward error correction (FEC) and modulation for fiber-optic communications. To this end, we use an information-theoretic design framework to investigate coded modulation (CM) techniques for standard additive white Gaussian noise (AWGN) channels and fiber-optic channels. This design guideline helps us provide a comprehensive overview of the CM schemes in the literature. Then, by invoking recent advances in optical channel modeling for nondispersion-managed links, we discuss two-dimensional (2-D) and four-dimensional (4-D) CM schemes. Moreover, we discuss the electronic computational complexity and hardware constraints of CM schemes for optical communications. Finally, we address CM schemes with signal shaping and rate-adaptation capabilities to accommodate the data transmission scheme to optical links with different signal qualities. © 1991-2012 IEEE.


Ekberg A.,Chalmers University of Technology | Akesson B.,Chalmers University of Technology | Kabo E.,Chalmers University of Technology | Kabo E.,Qamcom Research and Technology AB
9th International Conference on Contact Mechanics and Wear of Rail/Wheel Systems, CM 2012 | Year: 2012

With the aim of putting prediction and prevention of rolling contact fatigue of wheels and rails in context, the paper sets out with a description of the phenomena. This is followed by a discussion on predictive models with emphasis on influencing factors needed to be accounted for and how these can be incorporated in a predictive model. This forms the basis for a discussion on preventive measures. Finally a brief outlook of expected future trends is given.


Chen X.,Qamcom Research and Technology AB | Wolfgang A.,Qamcom Research and Technology AB
IEEE Vehicular Technology Conference | Year: 2016

In this paper, a carrier recovery scheme for phase noise mitigation (in the presence of imperfect synchronization and channel estimation) is proposed for orthogonal frequency division multiplexing (OFDM) based wireless backhaul. This scheme models the phase noise as a piece-wise linear function and compensate the phase noise within each OFDM symbol. It is shown that the carrier recovery scheme can be applied to both OFDM and orthogonal frequency-division multiple access (OFDMA). Since the proposed scheme does not require detailed knowledge of statistical properties of the phase noise, it can be easily applied to practical OFDM/OFDMA systems. Hence the proposed scheme is applicable to both point-to-point and point-to-multipoint backhauls. © 2016 IEEE.


Kildal P.-S.,Chalmers University of Technology | Chen X.,Chalmers University of Technology | Chen X.,Qamcom Research and Technology AB | Gustafsson M.,Huawei | Shen Z.,Huawei
IEEE Access | Year: 2014

Wireless systems have become more and more advanced in terms of handling the statistical properties of wireless channels. For example, the 4G long term evolution (LTE) system takes advantage of multiport antennas [multiple-input multiple-output (MIMO) technology] and orthogonal frequency division multiplexing (OFDM) to improve the detection probability of single bitstream by diversity in the spatial and frequency domains, respectively. The 4G system also supports transmission of two bitstreams by appropriate signal processing of the MIMO subchannels. The reverberation chamber emulates according to previous works rich isotropic multipath (RIMP) and has proven to be very useful for characterizing smart phones for LTE systems. The measured throughput can be accurately modeled by the simple digital threshold receiver, accounting accurately for both the MIMO and OFDM functions. The throughput is equivalent to the probability of detection (PoD) of the transmitted bitstream. The purpose of this paper is to introduce a systematic approach to include the statistical properties of the user and his or her terminal, when characterizing the performance. The user statistics will have a larger effect in environments with stronger line-of-sight (LOS), because the angle of arrival and the polarization of the LOS contribution vary due to the user's orientation and practices. These variations are stochastic, and therefore, we introduce the term random-LOS to describe this. This paper elaborates on the characterization of an example antenna in both RIMP and random-LOS. The chosen antenna is a wideband microbase transceiver station (BTS) antenna. We show how to characterize the micro-BTS by the PoD of one and two bitstreams in both RIMP and random-LOS, by considering the user randomly located and oriented within the angular coverage sector. We limit the treatment to a wall-mounted BTS antenna, and assume a desired hemispherical coverage. The angular coverages of both one and two bitstreams for the random-LOS case are plotted as MIMO-coverage radiation patterns of the whole four-port digital antenna system. Such characterizations in terms of PoD have never been done before on any practical antenna system. The final results are easy to interpret, and they open up a new world of opportunities for designing and optimizing 5G antennas on system level. © 2013 IEEE.


Karttunen K.,Chalmers University of Technology | Kabo E.,Chalmers University of Technology | Kabo E.,Qamcom Research and Technology AB | Ekberg A.,Chalmers University of Technology
Wear | Year: 2014

Optimised maintenance of railway tracks requires knowledge of how a deteriorated track geometry will affect subsequent damage of the track. In this study the influence on rolling contact fatigue (RCF) is investigated through numerical simulations featuring a freight wagon run on tracks with a single track irregularity or with a track irregularity spectrum generated from a power spectral density. Evaluated RCF impact is correlated to the track geometry to identify intrinsic properties of track geometry and irregularities that promote surface initiated RCF. On tangent track, simulations predict a single lateral irregularity with amplitude of 6. mm and length less than 20. m to be sufficient to cause RCF. For operations in shallow curves the simulations indicate that the most efficient RCF mitigation measure is to reduce the longwave content of the lateral irregularities. Furthermore, a study of the relation between track irregularity geometries and resulting wheel forces found a fairly weak correlation. © 2013 Elsevier B.V.


Karttunen K.,Chalmers University of Technology | Kabo E.,Chalmers University of Technology | Kabo E.,Qamcom Research and Technology AB | Ekberg A.,Chalmers University of Technology
Wear | Year: 2014

Current maintenance criteria of railway wheel geometries consider mainly flange thickness, flange height, flange gradient, and depth of thread wear. These geometrical quantities are relatively simple to evaluate, but do not fully describe neither the worn profile nor its influence on subsequent deterioration of wheel and rail. With increased use of automatic wheel profile measurements there is a potential to plan maintenance from measures that provide a more elaborate description of the wheel profile and its operational capabilities. To this end, the paper first outlines a procedure to parametrise worn wheel profiles. This procedure is linked to multibody simulations of a curve negotiating freight wagon to identify parameters of the worn wheel profile with the largest influence on rolling contact fatigue (RCF) and wear. To limit the number of parameter combinations, nearly orthogonal and space filling Latin hypercube sampling is employed. Regression analysis is then utilised to derive simple relationships (meta-models) between geometry parameters and deterioration measures. The derived meta-models of RCF and wear deterioration are shown to produce good agreement to results from fully fledged multibody simulations. The end result is identified geometrical quantities that provide an improved categorisation of the deteriorated wheel tread geometry for improved maintenance decisions. © 2014 Elsevier B.V.

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