| 1. |
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| 2. |
- Acatauassu, Diogo, et al.
(författare)
-
KHM cable model parameters for ITU-T G.Fast reference loops
- 2016
-
Ingår i: 2015 IEEE Conference on Standards for Communications and Networking, CSCN 2015. - 9781479989287 ; , s. 168-173
-
Konferensbidrag (refereegranskat)abstract
- G.Fast is a new standard for fixed broadband access that aims at achieving bit rates of 1 Gb/s over short copper loops. In order to give support to simulation, design and performance evaluation tests, the G.Fast recommendation presents examples of some wiring topologies and reference loops describing configurations expected to be found in real G.Fast deployments. Our work describes results of modeling some types of lines adopted in these reference loops by means of a low complexity and causal parametric cable model. The results indicate that the modeling approach proposed in this work is accurate for all the analyzed cases, which include high quality, medium quality and low quality cables.
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| 3. |
- Acatauassu, Diogo, et al.
(författare)
-
Simple and Causal Copper Cable Model Suitable for G.fast Frequencies
- 2014
-
Ingår i: IEEE Transactions on Communications. - 0090-6778. ; 62:11, s. 4040-4051
-
Tidskriftsartikel (refereegranskat)abstract
- G.fast is a new standard from the International Telecommunication Union, which targets 1 Gb/s over short copper loops using frequencies up to 212 MHz. This new technology requires accurate parametric cable models for simulation, design, and performance evaluation tests. Some existing copper cable models were designed for the very high speed digital subscriber line spectra, i.e., frequencies up to 30 MHz, and adopt assumptions that are violated when the frequency range is extended to G.fast frequencies. This paper introduces a simple and causal cable model that is able to accurately characterize copper loops composed by single or multiple segments, in both frequency and time domains. Results using G.fast topologies show that, apart from being accurate, the new model is attractive due to its low computational cost and closed-form expressions for fitting its parameters to measurement data.
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| 4. |
- Acatauassu, Diogo, et al.
(författare)
-
Simple and Causal Twisted-Pair Channel Models for G.fast Systems
- 2013
-
Ingår i: [Host publication title missing].
-
Konferensbidrag (refereegranskat)abstract
- The use of a hybrid copper and fiber architecture is attractive in both fixed access and mobile backhauling scenarios. This trend led the industry and academia to start developing the fourth generation broadband system, which aims at achieving bitrates of 1 Gbps over short copper loops. In this context, accurate models of short twisted-pair cables operating at relatively high frequencies are key elements. This work describes new parametric cable models that incorporate four important characteristics: support of frequencies up to 200 MHz, few parameters, causal impulse responses and require relatively easy fitting procedures. The results show that the models achieve good accuracy for single segments, which are the expected topology for G.fast deployments.
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| 5. |
- Andersson, Jens A, et al.
(författare)
-
Analytic Model for Cross-Layer Dependencies in VDSL2 access networks
- 2014
-
Ingår i: 22nd International Conference on Software, Telecommunications and Computer Networks (SoftCOM), 2014. - 9781479964970 - 9789532900521 ; , s. 269-273
-
Konferensbidrag (refereegranskat)abstract
- Recent changes in user employment of Internet based services, new deployment technologies for mobile networks as well as an ongoing realisation of fixed and mobile converged networks e.g. the EU FP7 project COMBO, are significant examples of enablers for increasing demands on DSL links. Investigating cross-layer dependencies between all layers in the OSI reference model becomes increasingly important. In this paper we present an analytical model and experimental results for the relation between impulse noise on a VDSL2 link and the effect this have on the network layer packet loss. We show how the packet loss rate is dependent not only on the disturbance signal level and periodicity but also on the link utilisation.
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| 6. |
- Andersson, Jens A, et al.
(författare)
-
Impact of DSL link impairments on higher layer QoS parameters
- 2012
-
Ingår i: Proceedings of SNCNW 2012. ; , s. 95-98
-
Konferensbidrag (refereegranskat)abstract
- An increasing demand from e.g. real-time multimedia applications (IPTV, OTT) adds strains on especially DSL based access links. In this paper we argue why it is important to study DSL link impairments and their impact on QoS parameters on higher layers. We discuss the need for establishing methods for quality of service estimation with cross layer techniques and present some initial results.
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| 7. |
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| 8. |
- Andersson, Jens A, et al.
(författare)
-
User profiling for pre-fetching or caching in a catch-up TV network
- 2016
-
Ingår i: 2016 IEEE International Symposium on Broadband Multimedia Systems and Broadcasting (BMSB). - 9781467390446
-
Konferensbidrag (refereegranskat)abstract
- We investigate the potential of different pre-fetching and/or caching strategies for different user behaviour with respect to surfing or browsing in a catch-up-TV network. To this end we identify accounts and channels associated with strong or weak surfing or browsing respectively and study the distributions of hold times for the different types of behaviour. Finally we present results from a request prediction model and a caching simulation for the different types of behaviour and find that the results are relatively similar.
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| 9. |
- Gosselin, Stéphane, et al.
(författare)
-
Fixed and Mobile Convergence: Needs and Solutions
- 2014
-
Konferensbidrag (refereegranskat)abstract
- The drivers of Fixed and Mobile Convergence (FMC) are discussed. A reference framework for FMC proposed by European project COMBO is then presented. Some use cases of FMC are described, showing the needs for mutualization and convergence of fixed and mobile broadband networks. Five network scenarios providing technical solutions to FMC use cases are proposed. They target an optimal and seamless quality of experience for the end user together with an optimized network infrastructure ensuring increased performance, flexibility, reduced cost and reduced energy consumption.
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| 10. |
- Handlery, Marc, et al.
(författare)
-
Some distance properties of tailbiting codes
- 2001
-
Ingår i: [Host publication title missing]. - 0780371232 ; , s. 290-290
-
Konferensbidrag (refereegranskat)abstract
- The active tailbiting segment distance for convolutional codes is introduced. Together with the earlier defined active burst distance, it describes the error correcting capability of a tailbiting code encoded by a convolutional encoder. Lower bounds on the new active distance as well as an upper bound on the ratio between tailbiting length and memory of the encoder such that its minimum
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| 11. |
- Huang, Yezi, et al.
(författare)
-
Enabling DSL and Radio on the Same Copper Pair
- 2015
-
Ingår i: 2015 IEEE International Conference on Communications (ICC). - 9781467364324 ; , s. 1031-1035
-
Konferensbidrag (refereegranskat)abstract
- To increase indoor coverage for mobile services, we propose a residential small cell infrastructure making use of the existing copper plant. The system is cabinet-based, collocated with VDSL2 and uses small pieces of spectrum next to VDSL2. Inspired by the Ericsson Radio Dot System, it challenges the femtocell paradigm offering full macro functionality in the small cells. An interesting service potential is offered albeit the added mobile traffic capacity is moderate as it is limited by the copper fronthaul.
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| 12. |
- Huang, Yezi, et al.
(författare)
-
LTE Over Copper - Potential and Limitations
- 2015
-
Ingår i: 2015 IEEE 26th Annual International Symposium on Personal, Indoor, and Mobile Radio Communications (PIMRC). - 9781467367820 ; , s. 1339-1343
-
Konferensbidrag (refereegranskat)abstract
- The densification of mobile networks in order to meet increased capacity demands is ongoing, needed and costly. A few papers have been published based on the insight that the fixed broadband networks offer a multitude of sites, for instance our homes, for potential small cell deployment providing backhaul capacity and power without site costs. However, in order to reach economical large-scale benefits, we explore the case when radio systems are deployed in coexistence with DSL. In this paper, we establish the feasibility of such a concept under constraints invoked by state-of-the-art and emerging systems (3GPP, VDSL2 and G.fast) and make statements about the required architecture. We also point out that the enthusiasm of previously published results should be lowered a notch.
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| 13. |
- Huang, Yezi, et al.
(författare)
-
Time-Domain Precoding for LTE-over-Copper Systems
- 2016
-
Ingår i: 2016 IEEE International Conference on Communications (ICC). - 9781479966646 - 9781479966653 ; , s. 1-6
-
Konferensbidrag (refereegranskat)abstract
- Crosstalk cancellation is a crucial issue for traditional digital subscriber line systems. For LTE-over-copper systems, however, the need for crosstalk cancellation varies depending on the analog fronthauling architecture and its parameters. A crosstalk handler that is decoupled as much as possible from the rest of the system architecture is thus preferred. Therefore, we propose a time-domain precoding scheme specifically in downstream direction to separate the precoding unit from the LTE signal flow, and perform crosstalk cancellation in an on-demand manner. Estimation of all direct and crosstalk paths is assisted by LTE cell-specific reference signals. The time-domain precoder transforms the interference channel into a crosstalk-free channel with identical direct paths, which allows for low-complexity inter-symbol interference mitigation. We evaluate the concept in terms of signal-to-noise ratio provided for LTE signals using measured wireline channel data.
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| 14. |
- Höst, Stefan, et al.
(författare)
-
A distance measure tailored to tailbiting codes
- 2002
-
Ingår i: Problems of Information Transmission. - 0032-9460. ; 38:4, s. 280-295
-
Tidskriftsartikel (refereegranskat)abstract
- The error-correcting capability of tailbiting codes generated by convolutional encoders is described. In order to obtain a description beyond what the minimum distance d min of the tailbiting code implies, the active tailbiting segment distance is introduced. The description of correctable error patterns via active distances leads to an upper bound on the decoding block error probability of tailbiting codes. The necessary length of a tailbiting code so that its minimum distance is equal to the free distance d free of the convolutional code encoded by the same encoder is easily obtained from the active tailbiting segment distance. This is useful when designing and analyzing concatenated convolutional codes with component codes that are terminated using the tailbiting method. Lower bounds on the active tailbiting segment distance and an upper bound on the ratio between the tailbiting length and memory of the convolutional generator matrix such that d min equals d free are derived. Furthermore, affine lower bounds on the active tailbiting segment distance suggest that good tailbiting codes are generated by convolutional encoders with large active-distance slopes.
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| 15. |
|
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| 16. |
- Höst, Stefan, et al.
(författare)
-
Active distances and cascaded convolutional codes
- 1997
-
Ingår i: [Host publication title missing]. - 0780339568 ; , s. 107-107
-
Konferensbidrag (refereegranskat)abstract
- A family of active distances for convolutional codes is introduced. Lower bounds are derived for the ensemble of periodically time-varying convolutional codes.
|
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| 17. |
- Höst, Stefan, et al.
(författare)
-
Active distances for convolutional codes
- 1999
-
Ingår i: IEEE Transactions on Information Theory. - : Institute of Electrical and Electronics Engineers (IEEE). - 0018-9448. ; 45:2, s. 658-669
-
Tidskriftsartikel (refereegranskat)abstract
- A family of active distance measures for general convolutional codes is defined. These distances are generalizations of the extended distances introduced by Thommesen and Justesen (1983) for unit memory convolutional codes. It is shown that the error correcting capability of a convolutional code is determined by the active distances. The ensemble of periodically time-varying convolutional codes is defined and lower bounds on the active distances are derived for this ensemble. The active distances are very useful in the analysis of concatenated convolutional encoders
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| 18. |
|
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| 19. |
- Höst, Stefan, et al.
(författare)
-
Cascaded convolutional codes
- 1998
-
Ingår i: Communication and Coding. - 0863802389 ; , s. 10-29
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)
|
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| 20. |
|
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| 21. |
|
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| 22. |
|
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| 23. |
- Höst, Stefan, et al.
(författare)
-
Low complexity computation of the BT0 Hilbert twisted pair cable model
- 2010
-
Ingår i: [Host publication title missing]. ; , s. 195-199
-
Konferensbidrag (refereegranskat)abstract
- By use of the Hilbert transform the standardized BT0 twisted pair cable model can be rederived as a causal model with lower order, denoted BT0$_H$. In the present contribution the computational complexity of the BT0$_H$ model is decreased as the Hilbert transform is approximated with a look-up table implemented as a polynomial approximation. This results in a model of lower complexity than BT0$_H$ and lower order than the original BT0 model. Finally a comparison on causality of the considered models is presented.
|
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| 24. |
- Höst, Stefan, et al.
(författare)
-
Network Requirements for Latency-Critical Services in a Full Cloud Deployment
- 2016
-
Ingår i: SoftCom 2016.
-
Konferensbidrag (refereegranskat)abstract
- The end-point of the cloud trend is that all compu- tational and storage resources leave the homes and move to the cloud. We can be rather certain the future eventually looks like this as IT and telecommunications services are commoditised and the end users’ time, interest and skill to acquire and maintain electronics fade away. The network architecture suitable for such scenario will be analysed in terms of latency critical services to establish delay requirements and feasible localisations of the data centers. It is concluded that for cloud gaming as an example of a time-critical service, the maximum delay is limited to 20 ms. In the network architecture this corresponds to locating the data center in the Main CO, i.e. typically in the aggregation part of a metropolitan network.
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| 25. |
- Höst, Stefan, et al.
(författare)
-
Nonequivalent cascaded convolutional codes obtained from equivalent constituent convolutional encoders
- 1998
-
Ingår i: Problems of Information Transmission. - 0032-9460. ; 34:4, s. 291-299, s. 338-338
-
Forskningsöversikt (refereegranskat)abstract
- Cascaded convolutional codes with conventional convolutional codes as constituent codes are powerful and attractive to use in communication systems where very low error probabilities are needed. This paper clearly demonstrates the dramatic effect the replacement of the inner convolutional encoder by an equivalent one could have on the cascaded convolutional code
|
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| 26. |
- Höst, Stefan, et al.
(författare)
-
On coded OFDM over frequency selective channels using woven convolutional codes
- 2003
-
Ingår i: Proceedings 2003 IEEE International Symposium on Information Theory. ISIT 2003 (Cat. No.03CH37432). - 0780377281 ; , s. 36-36
-
Konferensbidrag (refereegranskat)abstract
- A communication system with woven convolutional codes and OFDM is considered. With coherent reception and iterative decoding this combination seems promising over frequency selective channels. The robustness of the considered class of schemes is illustrated by simulation results for specific fixed channel transfer functions and AWGN
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| 27. |
|
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| 28. |
- Höst, Stefan, et al.
(författare)
-
On the distribution of the output error burst lengths for Viterbi decoding of convolutional codes
- 1997
-
Ingår i: [Host publication title missing]. - 0780339568 ; , s. 108-108
-
Konferensbidrag (refereegranskat)abstract
- The distribution of the output error burst lengths from a Viterbi decoder is of particular interest in connection with concatenated coding systems, where the inner code is convolutional. From the expurgated, random, and sphere-packing exponents for block codes an upper bound on this distribution for the ensemble of periodically time-varying convolutional codes is obtained. Finally, the distribution obtained from simulating time-invariant convolutional codes is presented
|
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| 29. |
- Höst, Stefan
(författare)
-
On Woven Convolutional Codes
- 1999
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Concatenation of several conventional convolutional encoders is a both powerful and practical method to obtain encoding schemes that are attractive for use in communication systems where very low error probabilities are needed. This thesis is devoted to woven convolutional codes, a construction where the constituent codes are woven together in a manner that resembles the structure of a fabric. A family of active distance measures for convolutional codes is defined. It is shown that the error correcting capability of a convolutional code is determined by the active distances. Lower bounds on the active distances are derived for the ensemble of periodically time-varying convolutional codes. The simplest construction of serially concatenated convolutional codes is considered, viz., a direct cascade of two convolutional encoders. Important structural properties for the cascaded convolutional encoder is shown both for the case of matched and for unmatched rates. Several interesting examples of cascaded convolutional codes are considered and examined. Lower bounds on the active distances and the free distance are derived for the ensemble of periodically time-varying cascaded convolutional codes. Woven convolutional codes can be viewed as a generalization of cascaded convolutional codes. The general construction is called the twill and it is described together with two important special cases, viz., woven convolutional codes with outer and inner warp. The woven convolutional encoder inherits many of its structural properties, such as minimality, from the constituent encoders. Distance properties for the constructions are examined and upper and lower bounds on the free distance are derived. Decoding of woven convolutional codes should be performed iteratively and, for that reason, the BCJR algorithm is rederived. Simulation results show that woven convolutional codes are attractive alternatives to the celebrated Turbo codes. Finally, a review of bounds, such as error exponents and bounds on the active distances, is given for woven convolutional codes.
|
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| 30. |
|
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| 31. |
|
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| 32. |
- Höst, Stefan, et al.
(författare)
-
Woven convolutional codes I: Encoder properties
- 2002
-
Ingår i: IEEE Transactions on Information Theory. - : Institute of Electrical and Electronics Engineers (IEEE). - 0018-9448. ; 48:1, s. 149-161
-
Tidskriftsartikel (refereegranskat)abstract
- Encoders for convolutional codes with large free distances can be constructed by combining several less powerful convolutional encoders. This paper is devoted to constructions in which the constituent convolutional codes are woven together in a manner that resembles the structure of a fabric. The general construction is called twill and it is described together with two special cases, viz., woven convolutional encoders with outer warp and with inner warp. The woven convolutional encoders inherit many of their structural properties, such as minimality and catastrophicity, from their constituent encoders. For all three types of woven convolutional codes upper and lower bounds on their free distances as well as lower bounds on the active distances of their encoders are derived.
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| 33. |
- Jordan, Ralph, et al.
(författare)
-
Decoding of woven convolutional codes and simulation results
- 2000
-
Ingår i: [Host publication title missing]. - 0780358570 ; , s. 96-96
-
Konferensbidrag (refereegranskat)abstract
- An iterative decoding scheme for woven convolutional codes is presented. It is called pipeline decoding and operates in a window sliding over the received sequence. This exploits the nature of convolutional codes as sequences and suits the concept of convolutional encoding and decoding as a continuous process. The pipeline decoder is analyzed in terms of decoding delay and decoding complexity. Additional interleaving for woven convolutional constructions is introduced by employing a convolutional scrambler. It is shown that some types of interleaving preserve the lower bound on the free distance of the original woven construction. Simulation results for woven convolutional codes are presented
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| 34. |
|
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| 35. |
- Jordan, R, et al.
(författare)
-
Woven convolutional codes II: Decoding aspects
- 2004
-
Ingår i: IEEE Transactions on Information Theory. - 0018-9448. ; 50:10, s. 2522-2529
-
Tidskriftsartikel (refereegranskat)abstract
- An iterative decoding scheme for woven convolutional codes is presented. It operates in a window sliding over the received sequence. This exploits the nature of convolutional codewords as infinite sequences and reflects the concept of considering convolutional encoding and decoding as a continuous process. The decoder is analyzed in terms of decoding delay and decoding complexity. Its basic building block is a symbol-by-symbol a posteriori probability (APP) decoder for convolutional codes, which is a windowed variant of the well-known Bahl-Cocke-Jelinek-Raviv (BCJR) algorithm. Additional interleaving for the woven constructions is introduced by employing convolutional scramblers. It is shown that row-wise random interleaving preserves the lower bound on the free distance of the original woven constructions. Based on the properties of the interleavers, new lower bounds on the free distance of woven constructions with both outer warp and inner warp are derived. Simulation results for woven convolutional codes with and without additional interleaving are presented.
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| 36. |
- Khadraoui, Younes, et al.
(författare)
-
On connection control and traffic optimisation in FMC networks
- 2016
-
Ingår i: 2015 IEEE 16th International Conference on High Performance Switching and Routing, HPSR 2015. - 9781479998715 ; 2016-June
-
Konferensbidrag (refereegranskat)abstract
- With the introduction of smartphones and tablets and the dramatical increase of the data traffic on the cellular network, operators are seeking for new solutions to provide the users with continuous connectivity while preserving a good quality of service. Since most of current user terminals are equipped with multiple interfaces, one solution is to take advantage of the different access networks. However, with the current network architectures and user application, it is not possible to use both accesses at the same time or even to switch from one to another without loosing current sessions. In this paper, we present and analyse the main mechanisms of the literature that allow a user to use multiple access networks at the same time or to move between the different networks. We show how a converged network can permit the deployment of new solutions and present some of them accompanied by use cases.
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| 37. |
- Lindholm, Christin, et al.
(författare)
-
A Case Study on Software Risk Analysis in Medical Device Development
- 2012
-
Ingår i: Software Quality. Process Automation in Software Development/Lecture Notes in Business Information Processing. - Berlin, Heidelberg : Springer Berlin Heidelberg. - 1865-1348. - 9783642272127 ; 94, s. 143-158
-
Konferensbidrag (refereegranskat)abstract
- Software failures in medical devices can lead to catastrophic situations. Therefore is it crucial to handle software related risks when developing medical devices. This paper presents the experiences gained from an ongoing case study with a medical device development organisation. This part of the study focuses on the two first steps of the risk management process, i.e. risk identification and risk analysis. The research is conducted as action research, with the aim of analysing and giving input to the organisation’s introduction of a software risk management process. The risk identification activities focus on user risks based on scenarios describing the expected use of the medical device in its target environment. Challenging problems have been found in the risk management process with respect to definition of the system boundary and system context, the use of scenarios as input to the risk identification and estimation of detectability used during risk assessment.
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| 38. |
- Lindholm, Christin, et al.
(författare)
-
Software risk analysis in medical device development
- 2011
-
Ingår i: Proceedings of the 37th EUROMICRO Conference on Software Engineering and Advanced Applications. - 9780769544885 ; , s. 362-365
-
Konferensbidrag (refereegranskat)abstract
- The purpose of risk management in the development of safety-critical software is to eliminate or reduce harmful behaviour. In health-care it is essential to manage risk related to software due to its increased use in medical devices and other computer systems. This paper presents some of the experiences gained from an ongoing case study at a large hospital in Sweden. The study focuses on identification and analysis of risks using scenarios and how effective this approach is. The research is conducted as action research, with the aim of analysing and giving input to the organisation’s new software risk management process.
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| 39. |
- Lindqvist, Fredrik, et al.
(författare)
-
Low-order and causal twisted-pair cable modeling by means of the Hilbert transform
- 2008
-
Ingår i: AIP Conference Proceedings. - : AIP. ; , s. 301-310
-
Konferensbidrag (refereegranskat)abstract
- A new low-order and causal twisted-pair cable model for the copper access network is derived. From the serial resistance of the widely used, but non-causal, BT0 model, the serial inductance is computed via the Hilbert transform. By doing so, a causal cable model is obtained containing fewer parameters compared to the BT0 model. The deviation between the two models is evaluated for the standardized ETSI cables.
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| 40. |
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| 41. |
- Medeiros, Eduardo, et al.
(författare)
-
Crosstalk Mitigation for LTE-over-Copper in Downlink Direction
- 2016
-
Ingår i: IEEE Communications Letters. - 1089-7798. ; 20:7, s. 1425-1428
-
Tidskriftsartikel (refereegranskat)abstract
- Radio-over-copper is a niche idea that has potential to become a cornerstone in the deployment of dense 5G networks. We address one of the remaining hurdles and present an architecture for transparent crosstalk mitigation in LTE-over-copper systems. By taking advantage of reference symbols present in the downlink LTE signals we propose two methods for estimating the copper channel. System performance is evaluated using channel measurements and error vector magnitude calculations with promising results.
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| 42. |
- Müller, Francisco, et al.
(författare)
-
Optimizing Power Normalization for G.fast Linear Precoder by Linear Programming
- 2014
-
Ingår i: 2014 IEEE International Conference on Communications, ICC 2014. - 9781479920037 ; , s. 4060-4065
-
Konferensbidrag (refereegranskat)abstract
- The use of vectoring for crosstalk cancellation in the new ITU-T G.fast standard for next generation DSL systems becomes essential for efficient utilization of the extended bandwidth (up to 200 MHz). In VDSL2 (up to 30 MHz), a zero-forcing-based linear precoder is used in downstream which approaches single-line performance. However, at high frequencies, the linear precoder may amplify the signal power substantially since the crosstalk channel is much stronger than at lower frequencies. Performance could be significantly degraded by power normalization to keep the PSD below the mask. In this work, we extended a per-line power normalization scheme by linear programming (LP) optimization. By simulations using measured cable data it is shown how the LPbased scheme further improves the linear precoder and it is also capable of balancing the data rate between lines. Further, the simulations also show the non-linear Tomlinson-Harashima precoder performs better than the linear precoders.
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| 43. |
- Ramalho, Leonardo, et al.
(författare)
-
An LPC-based fronthaul compression scheme
- 2017
-
Ingår i: IEEE Communications Letters. - 1089-7798. ; 21:2, s. 318-321
-
Tidskriftsartikel (refereegranskat)abstract
- Several new architectures are under investigation for cloud radio access networks, assuming distinct splits of functionality among the network elements. Consequently, the research on radio data compression for the fronthaul is based on assumptions that correspond to a wide variety of tradeoffs among data rate, signal distortion, latency, and computational cost. This letter describes a method for LTE downlink point-topoint signal compression based on linear prediction and Huffman coding, which is suitable for low cost encoding and decoding units with stringent restrictions on power consumption. The proposed method can work at various compression factors, such as 3.3:1 at an average EVM of 0.9%, or 4:1 at an average EVM of 2.1%.
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| 44. |
- Savi, Marco, et al.
(författare)
-
To distribute or not to distribute? Impact of latency on Virtual Network Function distribution at the edge of FMC networks
- 2016
-
Ingår i: 2016 18th International Conference on Transparent Optical Networks, ICTON 2016. - 2161-2064. - 9781509014675 ; 2016-August
-
Konferensbidrag (refereegranskat)abstract
- The Network Function Virtualization paradigm enables the possibility to dynamically instantiate Virtual Network Functions (VNFs) in Commercial-Off-The-Shelf (COTS) hardware. Such VNFs are then concatenated together in Service Chains (SCs) to provide specific Internet services to the users. Depending on latency requirements for such services and considering the aim of maximally consolidating the VNFs (i.e., of minimizing the COTS hardware), the VNFs can be centralized in few datacenters in the core network or they can be distributed closer to the edge of the network. In this paper we evaluate the impact of latency requirements of SCs on VNF distribution towards the edge of the network, by also showing the benefits of a Fixed and Mobile Convergent (FMC) metro/access network, with respect to a non-convergent network, in terms of consolidation.
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| 45. |
- Strandh, Magnus, et al.
(författare)
-
On robustness of turbo coded OFDM systems over frequency selective channels
- 2003
-
Ingår i: 8th International OFDM-Workshop.
-
Konferensbidrag (refereegranskat)abstract
- The robustness of fixed Turbo coded communication systems over frequency selective channels are investigated. The simulated amplitude functions are based on an idealised two level function and a decaying function. The results indicate that the system can cope with severe disturbances without to much loss.
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| 46. |
- Zyablov, Viktor V., et al.
(författare)
-
Asymptotic distance properties of binary woven convolutional codes
- 1999
-
Ingår i: Problems of Information Transmission. - 0032-9460. ; 35:4, s. 311-326
-
Tidskriftsartikel (refereegranskat)abstract
- Two constructions of binary concatenated convolutional codes are considered. In our previous work [Proc. 4th Int. Symp. Commun. Theory Appl., Lake District, UK (1997)] such codes were called woven convolutional codes. In the present paper, asymptotic lower bounds on active distances of woven convolutional codes are investigated. It is shown that these distances can be bounded from below by linearly growing functions with a strictly positive slope for all rates of concatenated codes, and the construction complexity of woven convolutional codes grows as an exponent of the memory of these codes.
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| 47. |
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| 48. |
- Zyablov, Viktor V., et al.
(författare)
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On the error exponent for woven convolutional codes with outer warps
- 1999
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Ingår i: IEEE Transactions on Information Theory. - : Institute of Electrical and Electronics Engineers (IEEE). - 0018-9448. ; 45:5, s. 1649-1653
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Tidskriftsartikel (refereegranskat)abstract
- In this correspondence the error exponent and the decoding complexity of binary woven convolutional codes with outer warp and with binary convolutional codes as outer and inner codes are studied. It is shown that an error probability that is exponentially decreasing with the product of the outer and inner code memories can be achieved with a nonexponentially increasing decoding complexity
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| 49. |
- Ödling, Per, et al.
(författare)
-
The fourth generation broadband concept
- 2009
-
Ingår i: IEEE Communications Magazine. - 0163-6804. ; 47:1, s. 63-69
-
Tidskriftsartikel (refereegranskat)abstract
- Fixed-broadband access technology is evolving from exclusively copper-based solutions to hybrid fiber-copper architectures. This article presents the expected next step in the evolution of broadband systems, which we call the fourth-generation broadband concept. It identifies a technical, infrastructural, and economical niche and describes how the fiber-access network is extended and forked to feed a last and ultimate generation of DSL systems, shown to have gigabit potential. The underlying infrastructural concept is presented, economic aspects are described and discussed, and achievable data rates are calculated.
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