| 1. |
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| 2. |
- Krishnan, Rajet, 1982, et al.
(författare)
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Variational Bayesian Framework for Receiver Design in the Presence of Phase Noise in MIMO Systems
- 2012
-
Ingår i: IEEE Wireless Communications and Networking Conference, WCNC. - 1525-3511. - 9781467304375 ; , s. 347-352
-
Konferensbidrag (refereegranskat)abstract
- In this work, the problem of receiver design for phasenoise estimation and data detection in the presence of oscillator phase noise in a point-to-point multiple-input multiple-output (MIMO) system is addressed. First, we discuss some interesting and challenging aspects in receiver design for MIMO systems in thepresence of Wiener phase noise. Then, using the variational Bayesian (VB) framework, a joint iterative phase noise estimator and symbol detector are developed based on inverse Gibbs or variational free energy maximization. Further, the symbol error probability (SEP) of the newly proposed iterative scheme is compared with the optimal ML detector with perfect phase information for 16-PSK and 16-QAM modulation schemes.
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| 3. |
- Sternad, Mikael, et al.
(författare)
-
Towards systems beyond 3G based on adaptive OFDMA transmission
- 2007
-
Ingår i: Proceedings of the IEEE. - 0018-9219 .- 1558-2256. ; 95:12, s. 2432-2455
-
Forskningsöversikt (refereegranskat)abstract
- High data rates, high spectral efficiency, flexibility, and low delays over the air interface will be important features in next-generation wireless systems. The overall challenge will be packet scheduling and adaptive radio transmission for multiple users, via multiple antennas and over frequency-selective wideband channels. This problem needs to be structured to obtain feasible solutions. The basic simplifying assumptions used here are clustering of antennas into cells, orthogonal transmission by use of cyclic-prefix orthogonal frequency-division multiplexing (OFDM) and a time-scale separation view of the total link adaptation, scheduling and intercell coordination problem. Based on these assumptions, we survey techniques that adapt the transmission to the temporal, frequency, and spatial channel properties. We provide a systematic overview of the design problems, such as the dimensioning of the allocated time-frequency resources, the influence of duplexing schemes, adaptation control issues for downlinks and uplinks, timing issues, and their relation to the required performance of channel predictors. Specific design choices are illustrated by recent research within the Swedish Wireless IP program and the EU IST-WINNER project. The presented results indicate that high-performance adaptive OFDM transmission systems are indeed feasible, also for challenging scenarios that involve vehicular velocities, high carrier frequencies, and high bandwidths
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| 4. |
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| 5. |
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| 6. |
- Svensson, Tommy, 1970, et al.
(författare)
-
Design and Performance of Constrained Envelope Continuous Phase Modulation
- 2009
-
Ingår i: Proceedings IEEE 4th International Waveform Diversity and Design Conference, Orlando, Florida, USA. - 9781424429714 ; , s. 312-316
-
Konferensbidrag (refereegranskat)abstract
- We have developed a coded modulation system withcontinuous phase and a small controlled envelope variation called Constrained Envelope Continuous Phase Modulation (ceCPM). For the spectrally efficient scenarios, within the ceCPM framework it is possible to find schemes with an SNR gain up to 2.5 dB over Continuous Phase Modulation (CPM) at symbol error probability 10−3, under the same requirement on spectral confinement and spectral efficiency as for the best CPM scheme. In this paper we discuss the design process for how to obtain such ceCPM schemes, and we elaborate on the properties of these ceCPM schemes.
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| 7. |
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| 8. |
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| 9. |
- Svensson, Tommy, 1970, et al.
(författare)
-
Multi-pulse Continuous Phase Modulation
- 2002
-
Ingår i: Proceedings 5th International Symposium on Wireless Personal Multimedia Communications, Honolulu, Hawaii, USA.
-
Konferensbidrag (refereegranskat)
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| 10. |
- Svensson, Tommy, 1970, et al.
(författare)
-
On Convolutionally Encoded Partial Response CPM
- 1999
-
Ingår i: Proceedings IEEE Vehicular Technology Conference Fall, Amsterdam, the Netherlands. ; , s. 663-667
-
Konferensbidrag (refereegranskat)
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| 11. |
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| 12. |
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| 13. |
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| 14. |
- Wang, Wei, 1965, et al.
(författare)
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Evaluations of a 4G Uplink System Based on Adaptive Single-Carrier TDMA
- 2005
-
Ingår i: Proceedings IEEE Vehicular Technology Conference Fall, Dallas, Texas, USA. - 1550-2252. - 0780391527 ; 3, s. 1667-1671
-
Konferensbidrag (refereegranskat)abstract
- © 2005 IEEE. Recent research has shown that a single-carrier system with frequency domain equalization can be a potential alternative to an OFDM-based system in a single user case. In this paper we propose and evaluate an adaptive single-carrier TDMA uplink with scheduling for broadband cellular packet data systems. Frequency division duplex (FDD) is assumed. Multiuser channel estimation and channel prediction are considered. The adaptive modulation scheme is optimized to maximize the throughput including also the ARQ part of the transmission. Frequency domain equalization is employed to combat the inter-symbol-interference (ISI). With the proposed design, the simulation results show that the multiuser diversity gain in spectral efficiency is limited in a wideband system, which indicates that an OFDM based system might be a more favorable candidate.
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| 15. |
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| 16. |
- Adinoyi, Abdulkareem, et al.
(författare)
-
EU FP6 IST-2003-507581 WINNER, D3.1 Description of identified new relay based radio network deployment, Oct 2004
- 2004
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- In D3.1 the first concept for a WINNER radio network deployment mainly focused on relay basedconcepts are proposed. Further the concept of an radio and protocol architecture is presented that takes upthe relaying approach as well as the idea of having different WINNER radio interface modes to servedifferent user and usage scenarios in an optimal manner. Thereby the presented protocol concept is basedon generic and mode specific user an control plane functionalities, where the common functions fordifferent modes are generalised and provide a common interface towards upper layer functions/protocols.Further some relaying concepts for urban hot area coverage including mesh networks are presentedaccompanied by promising simulation results. In addition to the relaying concepts benchmarks have beenproduced to allow a comparison of new concepts against today’s systems.
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| 17. |
- Adinoyi, Abdulkareem, et al.
(författare)
-
EU FP6 IST-2003-507581 WINNER, D3.2 Description of identified new relay based radio network deployment
- 2005
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Following the WINNER vision of a ubiquitous radio system providing wireless access for a wide range ofservices and applications across all environments D3.2 has consequently continued the work of D3.1towards a WINNER deployment concept. To cover the requirements of a WINNER RAN the flexiblenode architecture has been further elaborated. The envisaged WINNER modes are taken into account bymulti-mode protocol architecture that allows to exploit commonalities between different modes leading toa very flexible protocol and a close integration of the WINNER modes.The first steps towards concepts harmonisation are presented by categorising the large number ofdeployment concept proposals coming from D3.1 into logical groups. Further results on the comparisonbetween single-hop and multi-hop are shown in D3.2 accompanied by the presentation and assessment ofrelated routing strategies. Also the cooperative relaying concept has been driven forward and new resultshave been achieved in this field.Next to multi-hop, the single hop based deployment concepts have been elaborated partly with respect tonew air interface technologies. Finally D3.2 describes a system level simulation methodology to simulatethe deployment concepts based on the new WINNER air interface taking the agreed scenarios intoaccount.
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| 18. |
- Adinoyi, Abdulkareem, et al.
(författare)
-
EU FP6 IST-2003-507581 WINNER, D3.4 Definition and assessment of relay based cellular deployment concepts, June 2005
- 2005
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Following the WINNER vision of a ubiquitous radio system providing wireless access for a wide range ofservices and applications across all environments, D3.4 has continued the evolution of relay-baseddeployment concepts presented in D3.1 and D3.2 towards an understanding of the best deploymentconcepts for the envisioned WINNER scenarios. Continued work on concepts harmonization is reportedas well as evolved relaying concepts.
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| 19. |
- Antonakoglou, Konstantinos, et al.
(författare)
-
On the needs and requirements arising from connected and automated driving
- 2020
-
Ingår i: Journal of Sensor and Actuator Networks. - : MDPI AG. - 2224-2708. ; 9:2
-
Tidskriftsartikel (refereegranskat)abstract
- Future 5G systems have set a goal to support mission-critical Vehicle-to-Everything (V2X) communications and they contribute to an important step towards connected and automated driving. To achieve this goal, the communication technologies should be designed based on a solid understanding of the new V2X applications and the related requirements and challenges. In this regard, we provide a description of the main V2X application categories and their representative use cases selected based on an analysis of the future needs of cooperative and automated driving. We also present a methodology on how to derive the network related requirements from the automotive specific requirements. The methodology can be used to analyze the key requirements of both existing and future V2X use cases.
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| 20. |
- Aronsson, Daniel, et al.
(författare)
-
EU FP6 IST-4-027756 WINNER II, D2.3.3 Link level procedures for the WINNER System, Nov 2007
- 2007
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- In this deliverable, channel estimation algorithms, pilot design, measurement and signalling concepts, link and network synchronisation techniques, and the effects and remedies for RF impairments are described and evaluated for effective application in all WINNER modes, multiple access techniquesand deployment scenarios, for SISO and MIMO systems.
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| 21. |
- Aronsson, Daniel, et al.
(författare)
-
EU FP7 INFSO-ICT-247223 ARTIST4G, D3.4 Relay configurations
- 2011
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The following document contains proposals for innovations on relay configurations made by partners involved in the Artist4G project WP3, Task 3.3. The different relay configurations are for in-band and out-band relays, multi-hop relays, and moving relays. For each innovation, a description, the potential deviation from a defined baseline architecture, and simulation results (as far as available) are included. Important issues regarding the innovations impact on the architecture are pointed out and analysed in detail. This analysis will also be forwarded to WP4.
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| 22. |
- Aronsson, Daniel, et al.
(författare)
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Performance Evaluation of Memory-less and Kalman-based Channel Estimation for OFDMA
- 2009
-
Ingår i: VTC Spring 2009 - IEEE 69th Vehicular Technology Conference; Barcelona; Spain; 26 April 2009 through 29 April 2009. - 1550-2252. - 9781424425174 ; , s. Art. no. 5073788-
-
Konferensbidrag (refereegranskat)abstract
- The next generation wireless systems based onOrthogonal Frequency Division Multiple Access (OFDMA) needto operate in widely different deployment and usage scenarios. Thus, support for flexible resource allocation is important. In this paper we investigate the performance of different memory-less and memory-based channel estimators with different OFDMA subcarrier allocation schemes and different pilot patterns. We evaluate the performance in various fading environments and for different user terminal velocities. The results show that channel estimation can perform well enough for time-frequency localized resources as small as 22 channel symbols with two pilots in many important scenarios. The results provided can be used to identify appropriate subcarrier allocations for the next generation OFDMA based wireless systems.
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| 23. |
- Auer, Gunther, et al.
(författare)
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CELTIC CP5-026 WINNER+, D1.5 Intermediate Report on System Aspect of Advanced RRM
- 2009
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The deliverable describes the second set of best innovations proposed in the framework of the WP1 on system aspect of advanced Radio Resource Management (RRM) approved by the System Group. These concepts consist of promising innovative techniques and include an initial evaluation of the performance and benefits as far as already available. A brief description of each technique together with the relevant state of the art is provided.Moreover, first considerations about the requirements on the system, especially regarding measurements, signalling, architecture and protocols are described. The last set of innovations will be ready for the final deliverable of proof of concept evaluation.
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| 24. |
- Auer, Gunther, et al.
(författare)
-
EU FP6 IST-4-027756 WINNER II, D6.13.14 WINNER II System Concept Description, Dec 2007
- 2007
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This document contains a top-down view of the WINNER system with respect to logical node architecture, protocol architecture and cooperation architecture to give a basic understanding of the WINNER concept and as a complement to performance evaluations and design examples. The document also describes some of the important cross-layer optimizations that have been made. In addition to describing the concept, several example reference designs have been studied and are described.
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| 25. |
- Axnäs, Johan, et al.
(författare)
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EU FP6 IST-2003-507581 WINNER, D2.10 Final report on identified RI key technologies, system concept, and their assessment, Dec 2005
- 2005
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- A radio-interface concept for a ubiquitous WINNER radio system is presented and assessed,both in terms of performance and in terms of implementation complexity. The developed radio-interfaceconcept is a packet-oriented, user-centric, always-best concept targeting 100 Mbps sector-throughput forwide-area coverage and 1 Gbps for local-area coverage. It defines a scalable and flexible radio interfacebased on adaptive and compatible system modes that are tailored to particular situations such as the radioenvironment, the usage scenario, the economic model, etc. In contrast to the deliverable D7.6, whichfocuses on the functional architecture of the overall WINNER system concept, and D3.5, which describesprotocols and deployment concepts, the present deliverable focuses on the actual design of the radiointerface, primarily its lower layers, in order to enable optimisation and evaluation of performance.Results of extensive simulations on link, multi-link, and system levels are presented, supporting importantsystem design choices, exemplifying favourable configurations of the radio interface in differentscenarios, and providing an initial system performance estimation. Analyses of system complexity andimplementation issues are found not to reveal any major showstoppers that would prevent a cost-efficientimplementation at the time of deployment of the WINNER system.
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| 26. |
- Aydin, Osman, et al.
(author)
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EU FP7 INFSO-ICT-317669 METIS, D 4.1 Summary on preliminary trade-off investigations and first set of potential network-level solutions
- 2013
-
Reports (other academic/artistic)abstract
- METIS WP4 covers research activities in network-level aspects of the advancement of wireless network technologies towards the year 2020 and beyond. The aim is to develop novel network-level technology concepts to address the challenges foreseen in future scenarios with regard to interference, traffic and mobility management issues. Moreover, another task of this work package is to propose functional enablers which can support the above potential solutions.This document provides* a report of the ongoing progress in WP4 regarding the research topics agreed upon in IR 4.1,* a high level description of the proposed concepts and approaches adopted by different partners.More specifically, the document describes, first set of potential network-level solutions and presents some first research results in order to position them with regards to the state of the art approaches. It also gives an overview of research activities to be considered later in WP4.
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| 27. |
- Aydin, Osman, et al.
(author)
-
EU FP7 INFSO-ICT-317669 METIS, D4.2 Final report on trade-off investigations
- 2014
-
Reports (other academic/artistic)abstract
- Research activities in METIS WP4 include several aspects related to the network-level of future wireless communication networks. Thereby, a large variety of scenarios is considered and solutions are proposed to serve the needs envisioned for the year 2020 and beyond. This document provides vital findings about several trade-offs that need to be leveraged when designing future network-level solutions. In more detail, it elaborates on the following trade-offs:• Complexity vs. Performance improvement• Centralized vs. Decentralized• Long time-scale vs. Short time-scale• Information Interflow vs. Throughput/Mobility enhancement• Energy Efficiency vs. Network Coverage and CapacityOutlining the advantages and disadvantages in each trade-off, this document serves as a guideline for the application of different network-level solutions in different situations and therefore greatly assists in the design of future communication network architectures.
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| 28. |
- Azimi-Abarghouyi, Seyed Mohammad, et al.
(author)
-
Coverage analysis of finite cellular networks: A stochastic geometry approach
- 2018
-
In: IWCIT 2018 - Iran Workshop on Communication and Information Theory. - 9781538641491 ; , s. 1-5
-
Conference paper (peer-reviewed)abstract
- This paper develops a tractable modeling and analysis framework for finite cellular wireless networks using stochastic geometry. Defining finite homogeneous Poisson point processes to model the number and locations of access points in a confined region, we study the coverage probability for an arbitrarily-located reference user that is served by the closest access point. The distance distribution and the Laplace transform (LT) of the interference are derived. We also derive a closed-form lower bound on the LT of the interference. Our analyses reveal that a higher path loss exponent improves the coverage probability and that there is a location where the coverage probability is maximized.
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| 29. |
- Azimi-Abarghouyi, Seyed Mohammad, et al.
(author)
-
Decentralized Compute-and-Forward for Ad Hoc Networks
- 2016
-
In: IEEE Wireless Communications Letters. - : Institute of Electrical and Electronics Engineers (IEEE). - 2162-2345 .- 2162-2337. ; 5:6, s. 652-655
-
Journal article (peer-reviewed)abstract
- In this letter, we introduce a decentralized compute-and-forward (DCMF) protocol to solve the rank failure problem in compute-and-forward (CMF) ad hoc multi-user multi-relay networks without a central coordinator. In sufficiently strong inter-relay links, we show that the DCMF scheme can reach the same achievable rate as in the successive centralized CMF (SCCMF), which is a modified version of the previously introduced centralized CMF in using our proposed successive method for a fair comparison. We evaluate the outage probability and rate of the proposed strategy, and compare the results with those of the conventional CMF and decode-and-forward, and the SCCMF.
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| 30. |
- Azimi-Abarghouyi, Seyed Mohammad, et al.
(author)
-
Integer-Forcing Message Recovering in Interference Channels
- 2018
-
In: IEEE Transactions on Vehicular Technology. - 0018-9545 .- 1939-9359. ; 67:5, s. 4124-4135
-
Journal article (peer-reviewed)abstract
- In this paper, we propose a scheme referred to as integer-forcing message recovering (IFMR) to enable receivers to recover their desirable messages in interference channels. Compared to the state-of-the-art integer-forcing linear receiver (IFLR), our proposed IFMR approach needs to decode considerably less number of messages. In our method, each receiver recovers independent linear integer combinations of the desirable messages each from two independent equations. We propose an efficient polynomial-time algorithm to sequentially find the equations and integer combinations with maximum rates and analyze its complexity. We evaluate the performance of our scheme and compare the results with the minimum mean-square error linear receiver (MMSELR) and lattice-reduction-aided successive interference cancellation with signal-to-interference-plus-noise ratio maximizing preprocessing (LaR-aided SIC with SINR-Max), as well as the IFLR schemes. The results indicate that our IFMR scheme outperforms the MMSELR and LaR-aided SIC with SINR-Max schemes, in terms of achievable rate, considerably. Also, compared to the IFLR, the IFMR scheme achieves slightly less rates in moderate signal-to-noise ratios, with significantly less overall implementation complexity.
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| 31. |
- Azimi-Abarghouyi, Seyed Mohammad, et al.
(author)
-
Stochastic Geometry Modeling and Analysis of Finite Millimeter Wave Wireless Networks
- 2019
-
In: IEEE Transactions on Vehicular Technology. - 0018-9545 .- 1939-9359. ; 68:2, s. 1378-1393
-
Journal article (peer-reviewed)abstract
- This paper develops a stochastic geometry-based approach for the modeling and analysis of finite millimeter wave (mm Wave) wireless networks where a random number of transmitters and receivers are randomly located inside a finite region. We consider a selection strategy to serve a reference receiver by the transmitter providing the maximum average received power among all transmitters. In our system model, we employ the unique features of mm Wave communications such as directional transmit and receive beamforming and different channels for line-of-sight (LOS) and non-line-of-sight (NLOS) links. Accordingly, deploying a blockage process suitable for mm Wave networks, we study the coverage probability and the ergodic rate for the reference receiver that can be located everywhere inside the network region. As key steps for the analyses, the distribution of the distance from the reference receiver to its serving LOS or NLOS transmitter and LOS and NLOS association probabilities are derived. We also derive the Laplace transform of the interferences from LOS and NLOS transmitters. Finally, we propose upper and lower bounds on the coverage probability that can be evaluated easier than the exact results, and investigate the impact of different parameters including the receiver location, the beamwidth, and the blockage process exponent on the system performance.
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| 32. |
- Azimi-Abarghouyi, Seyed Mohammad, et al.
(author)
-
Stochastic geometry modeling and analysis of single- and multi-cluster wireless networks
- 2018
-
In: IEEE Transactions on Communications. - 0090-6778 .- 1558-0857. ; 66:10, s. 4981-4996
-
Journal article (peer-reviewed)abstract
- This paper develops a stochastic geometry-based approach for the modeling and analysis of single- and multi-cluster wireless networks. We first define finite homogeneous Poisson point processes to model the number and locations of the transmitters in a confined region as a single-cluster wireless network. We study the coverage probability for a reference receiver for two strategies; closest-selection, where the receiver is served by the closest transmitter among all transmitters, and uniform-selection, where the serving transmitter is selected randomly with uniform distribution. Second, using Matern cluster processes, we extend our model and analysis to multi-cluster wireless networks. Here, two types of receivers are modeled, namely, closed- and open-access receivers. Closed-access receivers are distributed around the cluster centers of the transmitters according to a symmetric normal distribution and can be served only by the transmitters of their corresponding clusters. Open-access receivers, on the other hand, are placed independently of the transmitters and can be served by all transmitters. In all cases, the link distance distribution and the Laplace transform (LT) of the interference are derived. We also derive closed-form lower bounds on the LT of the interference for single-cluster wireless networks. The impact of different parameters on the performance is also investigated.
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| 33. |
- Bai, Bo, et al.
(author)
-
Caching based socially-aware D2D communications in wireless content delivery networks: a hypergraph framework
- 2016
-
In: IEEE Wireless Communications. - 1536-1284 .- 1558-0687. ; 23:4, s. 74-81
-
Journal article (peer-reviewed)abstract
- The emergence of the D2D communications paradigm has transformed the way in which cellular networks are operated. Previous work in D2D communications, however, mainly focused on interference management and capacity maximization of both D2D links and cellular links. Recent literature has observed that the QoE can be greatly enhanced by caching contents in mobile devices, with a carefully designed caching strategy. In this article, we propose a novel hypergraph framework that designs the caching based D2D communication scheme by taking social ties among users and common interests into consideration. We first present the considered features of the D2D transmission scheme, social characteristics consideration, and interest similarity impact. The key concepts of hypergraph and related techniques, such as hypergraph coloring and multidimensional matching, are explained. Then some design issues with simulation results in the proposed framework are discussed in detail, which show the potential of the proposed approach. By jointly considering social ties, common interests, and the D2D transmission scheme, we believe the proposed framework explores new opportunities and future directions in caching based socially-aware D2D communications.
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| 34. |
- Baianifar, Mahdi, et al.
(author)
-
Effect of users height distribution on the coverage of mmwave cellular networks with 3d beamforming
- 2019
-
In: IEEE Access. - 2169-3536 .- 2169-3536. ; 7, s. 68091-68105
-
Journal article (peer-reviewed)abstract
- In this paper, we study the effect of users' height distribution on the coverage probability of millimeter-wave (mmWave) cellular networks that utilize three-dimensional beamforming (3DBF). The users and base stations (BSs) are equipped with multiple antennas and both line-of-sight (LOS) and non-LOS links exist in the channel which are, respectively, modeled by the Nakagami-m and Rayleigh distribution. In this setup, we investigate the tilt angle optimization of the BS antenna arrays for maximizing the coverage probability under two regimes of noise limited and interference limitedd. In both cases, by adopting a stochastic geometry approach, we analytically derive the coverage probability, and then, find the optimal tilt angle that maximizes this probability. In addition, in the noise limited regime, we show that the optimal tilt angle depends on the average distance between each user and its serving BS and also their effective height. In the interference-limited regime, we further consider different rules for associating users to the BSs. Meanwhile, since in this regime, the tilt angle optimization is very complex, we propose a low complexity approach to find the optimal tilt angle that has a performance close to the optimal solution. We further study the asymptotic behavior when the density of the BSs or signal-To-interference ratio tends to infinity or zero. Finally, through the numerical simulations, we show that using the 3DBF and also incorporating the users' height distribution in the tilt angle optimization lead to a substantial improvement in the coverage probability of the mmWave cellular networks.
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| 35. |
- Baianifar, Mahdi, et al.
(author)
-
Impact of User Height on the Coverage of 3D Beamforming-Enabled Massive MIMO Systems
- 2017
-
In: 2017 IEEE 28TH ANNUAL INTERNATIONAL SYMPOSIUM ON PERSONAL, INDOOR, AND MOBILE RADIO COMMUNICATIONS (PIMRC). - 9781538635315 ; 2017-October, s. 1-5
-
Conference paper (peer-reviewed)abstract
- In this paper, we perform a coverage analysis of a cellular massive multiple-input multiple-output (MaMIMO) network which adopts 3D beamforming. In contrast to the previous works on 3D beamforming which assume that all users are placed on the ground (i.e., in a 2D environment), we consider a more practical scenario where the users of the network are dropped in a 3D environment with different heights. In this scenario, by adopting a stochastic geometry framework, first we calculate the coverage probability of the network as a function of the users height. Then considering this coverage probability as the objective function, the optimum tilt angle of the base stations antenna pattern is found and the effect of users' heights on this tilt angle is investigated. Our numerical results show that by taking the users' heights into account and using the proposed method, a considerable improvement is achieved in the performance of the network compared to other similar 3D beamforming methods that ignore the users' height distribution.
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| 36. |
- Behravan, Ali, 1971, et al.
(author)
-
Positioning and Sensing in 6G: Gaps, Challenges, and Opportunities
- 2023
-
In: IEEE Vehicular Technology Magazine. - 1556-6080 .- 1556-6072. ; 18:1, s. 40-48
-
Journal article (peer-reviewed)abstract
- Among the key differentiators of 6G compared to 5G will be the increased emphasis on radio-based positioning and sensing. These will be utilized not only for conventional location-aware services and for enhancing communication performance but also to support new use case families with extreme performance requirements. This article presents a unified vision from stakeholders across the value chain in terms of both opportunities and challenges for 6G positioning and sensing as well as use cases, performance requirements, and gap analysis. Combined, this motivates the technical advances in 6G and guides system design.
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| 37. |
- Bengtsson, Mats, et al.
(author)
-
CELTIC CP5-026 WINNER+, D1.4 Initial Report on Advanced Multiple Antenna Systems
- 2008
-
Reports (other academic/artistic)abstract
- This deliverable captures the first set of best innovative concepts identified in the field of Advanced Multiple Antenna Systems for potential inclusion into the WINNER+ system concept. The concepts consist of promising principles or ideas as well as detailed innovative techniques. For each concept, the associated benefits as well as the corresponding requirements on the system architecture and protocols, measurements and signalling, are considered. The document involves two main tracks: development of new advanced antenna schemes in the context of conventional cellular networks, and a study of coordinated multipoint transmission and reception, where multiple network nodes cooperate to enhance system performance.
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| 38. |
- Bockelmann, C., et al.
(author)
-
Massive Machine-Type Communications in 5G: Physical and MAC-Layer Solutions
- 2016
-
In: IEEE Communications Magazine. - 0163-6804 .- 1558-1896. ; 54:9, s. 59-65
-
Journal article (peer-reviewed)abstract
- MTC are expected to play an essential role within future 5G systems. In the FP7 project METIS, MTC has been further classified into mMTC and uMTC. While mMTC is about wireless connectivity to tens of billions of machine-type terminals, uMTC is about availability, low latency, and high reliability. The main challenge in mMTC is scalable and efficient connectivity for a massive number of devices sending very short packets, which is not done adequately in cellular systems designed for human-type communications. Furthermore, mMTC solutions need to enable wide area coverage and deep indoor penetration while having low cost and being energy-efficient. In this article, we introduce the PHY and MAC layer solutions developed within METIS to address this challenge.
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| 39. |
- Boldi, Mauro, et al.
(author)
-
CELTIC CP5-026 WINNER+, D1.8 Intermediate Report on CoMP (Coordinated Multi-Point) and Relaying in the Framework of CoMP.
- 2009
-
Reports (other academic/artistic)abstract
- This deliverable is an intermediate report on CoMP (Coordinated Multi-Point) and on Relaying in the Framework of CoMP. It describes the second set of innovations encompassing concepts about promising principles or ideas as well as detailed innovative techniques in the framework of WINNER+ system concept. For each concept, the associated benefits as well as the corresponding requirements on the system architecture and protocols, measurements and signalling, are considered. Regarding CoMP algorithms, focus is put on schemes with reduced requirements in terms of backhauling considering two categories: “Coordinated Beamforming”, and “Joint Processing”. As for relaying, a relay-assisted interference channel, and a distributed LDPC coding for a Decode and Forward relay are introduced.
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| 40. |
- Boldi, M., et al.
(author)
-
Coordinated MultiPoint (CoMP) Systems
- 2011
-
In: Mobile and Wireless Communications for IMT-Advanced and Beyond. - : Wiley. - 9781119993216 ; , s. 121-155
-
Book chapter (other academic/artistic)
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| 41. |
- Boldi, Mauro, et al.
(author)
-
Coordinated MultiPoint Systems for IMT-Advanced in the Framework of Winner+ Project
- 2009
-
In: Proc. ICT Mobile Summit 2009, Santander, Spain, June 2009.
-
Conference paper (peer-reviewed)abstract
- The growing demand for improved performance in cellular radio networks led to the investigation of novel techniques able to cope for these needs. One of the most promising, currently evaluated in the framework of standardization bodies following ITU-R process for IMT-Advanced, is the so-called Coordinated MultiPoint (CoMP) access network architecture and related approaches and algorithms. CoMP is one of the most extensively studied topics in the context of Winner+ CELTIC European project. CoMP brings forward the concept of Advanced Antenna systems, introducing a degree of collaboration among a multiplicity of nodes exchanging information among them. Consequently, CoMP aims to exploit concurrently signals coming from all the nodes, transforming inter-cell interfering signals in useful ones, especially for cell-border users. In this paper some possible CoMP architectures are listed and the first results of simulations on CoMP systems, starting from ideal assumptions, are reported.
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| 42. |
- Bonneville, Hervé, et al.
(author)
-
EU FP7 INFSO-ICT-247223 ARTIST4G, D3.2 Advanced Relay Technical Proposals
- 2011
-
Reports (other academic/artistic)abstract
- The following document contains technical proposals for advanced relays that have been developed so far by the partners in Task 3.1 of WP3. The proposals are grouped according to the respective activity in Task 3.1 and contain a description of the innovation and all deviations from the baseline assumptions listed for state-of-the-art relay-enhanced systems in the first part of this document. For each innovation, analytical derivations and/or simulation results are provided, as well as an outlook on future work within WP3.
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| 43. |
- Botella Mascarell, Carmen, 1979, et al.
(author)
-
A low-complexity joint power control and beamforming algorithm for the downlink of multi-user W-CDMA coordinated systems
- 2009
-
In: Proc. IEEE International Workshop on Signal Processing Advances for Wireless Communications (SPAWC09), June 2009. - 9781424436965 ; , s. 226-230
-
Conference paper (peer-reviewed)abstract
- The downlink of aW-CDMA system with coordination betweenseveral base stations is considered throughout this paper. Within the framework of the power minimization problem, two Joint Power Control and Optimal Beamforming (JPCOB) algorithms have already been proposed in previous works. However, one of the major challenges associated with network coordination is the design of algorithms which result in low-complexity requirements as the number of users increases. In this paper, one of the previous JPCOBalgorithms is modified in order to obtain a low-complexity solution by reducing the amount of feedback required from the users in the system. The performance of this algorithm is then compared with the previous JPCOB solutions. Simulation results show that the low-complexity algorithm equals the performance of the previous solutions for a given number of coordinated base stations. However,it suffers a severe penalty for scenarios with high SINR requirements at the users. In order to overcome this drawback, two iterative schemes based on the particular structure of the matrices involved in the power control updating step are proposed. Moreover, these schemes could be seen as efficient and computationally simple scheduling techniques.
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| 44. |
- Botella Mascarell, Carmen, 1979, et al.
(author)
-
EU FP7 INFSO-ICT-247223 ARTIST4G, D1.3 Innovative scheduling and cross-layer design techniques for interference avoidance
- 2011
-
Reports (other academic/artistic)abstract
- This document provides an overview of the proposed innovations and activities in Task 1.2 of Work Package 1 (WP1) of the ARTIST4G project, related to interference avoidance. Focus is on the technical approaches applicable at layer 2, which are grouped into five different classes of innovations related to clustering & user grouping, inter-cell interference coordination, coordinated scheduling, scheduling for joint processing and gametheory based scheduling. Descriptions of the proposed innovations are given including basic ideas, potential of performance, simulation results, realization options and possible implementation restrictions.
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| 45. |
- Botella Mascarell, Carmen, 1979, et al.
(author)
-
On the performance of joint processing schemes over the cluster area
- 2010
-
In: IEEE Vehicular Technology Conference Spring, Taipei, Taiwan, May 2010. - 1550-2252. - 9781424425181 ; 2010-January, s. 1-5
-
Conference paper (peer-reviewed)abstract
- In this paper, three joint processing schemes for the downlink are characterized and compared within a cluster of base stations. The motivation of this study is to analyze the performance of these schemes over the cluster area, as a first step towards designing an adaptive joint processing scheme supporting dynamic usage scenarios. Each one of the analyzed schemes, the centralized, partial and distributed joint processing approaches, requires a different amount of available channel knowledge at the transmitter side, inter-base information exchange and feedback from the users. In addition, these schemes show varying capabilities to serve the users depending on their location in the cluster area. Therefore, in a real scenario, an adaptive joint processing scheme encompassing the three schemes could be used by the cluster of base stations. Simulation results show that, assuming coherent transmission, the centralized joint processing scheme outperforms with 25% the partial joint processing scheme and with 50% the distributed joint processing approach in the cell edge when a backhaul-load weighted average sum-rate per cell metric is taken into account.
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| 46. |
- Carvalho, E. de, et al.
(author)
-
EU FP7 INFSO-ICT-317669 METIS, D3.1 Positioning of multi-node/multi-antenna technologies
- 2013
-
Reports (other academic/artistic)abstract
- This document describes the research activity in multi-node/multi-antenna technologies within METIS and positions it with respect to the state-of-the-art in the academic literature and in the standardization bodies. Based on the state-of-the-art and as well as on the METIS objectives,we set the research objectives and we group the different activities (or technology components) into research clusters with similar research objectives. The technologycomponents and the research objectives have been set to achieve an ambidextrous purpose. On one side we aim at providing the METIS system with those technological components that are a natural but non-trivial evolution of 4G. On the other side, we aim at seeking for disruptivetechnologies that could radically change 5G with respect to 4G. Moreover, we mapped the different technology components to METIS’ other activities and to the overall goals of theproject.
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| 47. |
-
Cellular V2X for Connected Automated Driving
- 2021
-
Editorial collection (peer-reviewed)abstract
- Cellular vehicle-to-everything (C-V2X) technologies enable vehicles to communicate both with the network, with each other, and with other road users using reliable, responsive, secure, and high-capacity communication links. Cellular V2X for Connected Automated Driving provides an up-to-date view of the role of C-V2X technologies in connected automated driving (CAD) and connected road user (CRU) services, such as advanced driving support, improved road safety, infotainment, over-the-air software updates, remote driving, and traffic efficiency services enabling the future large-scale transition to self-driving vehicles. This timely book discusses where C-V2X technology is situated within the increasingly interconnected ecosystems of the mobile communications and automotive industries. An expert contributor team from both industry and academia explore potential applications, business models, standardization, spectrum and channel modeling, network enhancements, security and privacy, and more. Broadly divided into two parts—introductory and advanced material—the text first introduces C-V2X technology and introduces a variety of use cases and opportunities, requiring no prerequisite technical knowledge. The second part of the book assumes a basic understanding of the field of telecommunications, presenting technical descriptions of the radio, system aspects, and network design for the previously discussed applications. This up-to-date resource: Provides technical details from the finding of the European Commission H2020 5G PPP 5GCAR project, a collaborative research initiative between the telecommunications and automotive industries and academic researchers. Elaborates on use cases, business models, and a technology roadmap for those seeking to shape a start-up in the area of automated and autonomous driving. Provides up to date descriptions of standard specifications, standardization and industry organizations and important regulatory aspects for connected vehicles. Provides technical insights and solutions for the air interface, network architecture, positioning and security to support vehicles at different automation levels. Includes detailed tables, plots, and equations to clarify concepts, accompanied by online tutorial slides for use in teaching and seminars Thanks to its mix of introductory content and technical information, Cellular V2X for Connected Automated Driving is a must-have for industry and academic researchers, telecom and automotive industry practitioners, leaders, policymakers, and regulators, and university-level instructors and students.
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| 48. |
- Chai, R., et al.
(author)
-
Optimal joint utility based load balancing algorithm for heterogeneous wireless networks
- 2014
-
In: Wireless Networks. - : Springer Science and Business Media LLC. - 1022-0038 .- 1572-8196. ; 20:6, s. 1557-1571
-
Journal article (peer-reviewed)abstract
- The rapid development of mobile broadband services with continuously increasing traffic volumes has resulted in a number of challenges, including ubiquitous network coverage, high bandwidth, and reliable services for reasonable price, etc. To address these challenges, evolved packet system (EPS) is proposed as the evolution of the packet core network. While resource management and load balancing issues in EPS are discussed in 3GPP standardization, relatively few research works consider mechanism design for load information monitoring and evaluation. Furthermore, even though some load balancing algorithms have been proposed for integrated networks, the load balancing scheme design which achieves the optimization of joint system performance has not been extensively studied. In this paper, an inter-access system anchor based load balancing mechanism is introduced which performs load monitoring and evaluation for access gateways and networks, and an optimal load balancing algorithm is proposed for heterogeneous integrated networks. To characterize the performance of integrated networks, the concept of utility function is introduced and the comprehensive performance of integrated networks which support both single type service and multimedia service is modeled mathematically. Applying vertical handoff as an efficient mechanism for achieving load balancing, the optimal number of handoff users is obtained through solving the optimization problem. Numerical results demonstrate that load balancing between access networks can be achieved, and the optimal number of handoff users corresponding to the maximal joint network utility can be obtained.
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| 49. |
- Chai, R., et al.
(author)
-
Utility-based bandwidth allocation algorithm for heterogeneous wireless networks
- 2013
-
In: Science in China, Series F: Information Sciences. - : Springer Science and Business Media LLC. - 1009-2757 .- 1862-2836. ; 56:2, s. 95-107
-
Journal article (peer-reviewed)abstract
- In next generation wireless network (NGWN), mobile users are capable of connecting to the core network through various heterogeneous wireless access networks, such as cellular network, wireless metropolitan area network (WMAN), wireless local area network (WLAN), and ad hoc network. NGWN is expected to provide high-bandwidth connectivity with guaranteed quality-of-service to mobile users in a seamless manner; however, this desired function demands seamless coordination of the heterogeneous radio access network (RAN) technologies. In recent years, some researches have been conducted to design radio resource management (RRM) architectures and algorithms for NGWN; however, few studies stress the problem of joint network performance optimization, which is an essential goal for a cooperative service providing scenario. Furthermore, while some authors consider the competition among the service providers, the QoS requirements of users and the resource competition within access networks are not fully considered. In this paper, we present an interworking integrated network architecture, which is responsible for monitoring the status information of different radio access technologies (RATs) and executing the resource allocation algorithm. Within this architecture, the problem of joint bandwidth allocation for heterogeneous integrated networks is formulated based on utility function theory and bankruptcy game theory. The proposed bandwidth allocation scheme comprises two successive stages, i.e., service bandwidth allocation and user bandwidth allocation. At the service bandwidth allocation stage, the optimal amount of bandwidth for different types of services in each network is allocated based on the criterion of joint utility maximization. At the user bandwidth allocation stage, the service bandwidth in each network is optimally allocated among users in the network according to bankruptcy game theory. Numerical results demonstrate the efficiency of the proposed algorithm.
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| 50. |
- Chen, Houfeng, et al.
(author)
-
Near-Far Field Channel Modeling for Holographic MIMO Using Expectation-Maximization Methods
- 2024
-
In: IEEE Wireless Communications and Networking Conference, WCNC. - 1525-3511.
-
Conference paper (peer-reviewed)abstract
- Holographic Multiple-Input Multiple-Output (HMIMO), which densely integrates numerous antennas into a limited space, is anticipated to provide higher rates for future 6G wireless communications. The increase in antenna aperture size makes the near-field region enlarge, causing some users to be located in the near-field region. Thus, we are facing a hybrid near-field and far-field communication problem, where conventional far-field modeling methods may not work well. In this paper, we propose a near-far field channel model that does not presuppose whether each path is near-field or far-field, different from the existing work requiring the ratio of the number of near-field paths to that of far-field paths as prior knowledge. However, this gives rise to a new challenge for accurately modeling the channel, as conventional methods of obtaining channel model parameters are not applicable to this model. Therefore, we propose a new method, Expectation-Maximization (EM)-based Near-Far Field Channel Modeling, to obtain channel model parameters, which considers whether each path is near-field or far-field as a hidden variable, and optimizes the hidden variables and channel model parameters through an alternating iteration method. Simulation results show that our method is superior to conventional near-field and far- field algorithms in fitting the near-far field channel in terms of outage probability.
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