المؤلفون: Tommy Svensson, Xiaofeng Tao, Xiaoxuan Tang, Xiaodong Xu

المصدر: IEEE Access, Vol 5, Pp 13001-13009 (2017)

مصطلحات موضوعية: Smart city, General Computer Science, Computer science, business.industry, coverage probability, stochastic geometry, General Engineering, 020302 automobile design & engineering, 020206 networking & telecommunications, 02 engineering and technology, coordination multipoint joint transmission, moving relay (MR), law.invention, Backhaul (telecommunications), 0203 mechanical engineering, Relay, law, 0202 electrical engineering, electronic engineering, information engineering, Cellular network, General Materials Science, lcsh:Electrical engineering. Electronics. Nuclear engineering, business, lcsh:TK1-9971, Computer network

الوصف: Communication plays a significant role in terms of providing connectivity for urban users as well as sensors in smart cities. It has been shown that better communication capability for vehicular users can be obtained by introducing moving relays (MRs). With MRs, it is possible for macro base stations and moving relays to serve non-vehicular macro-users by performing coordinated multipoint (CoMP) joint transmission (JT). A bias-based CoMP scheme for MR enabled cellular network is analyzed in this paper. Motivated by antenna design constraints, in this paper, we assume that the outdoor antenna system of the MR can only be used for the moving backhaul link, i.e., the in-vehicle antenna system is also serving the non-vehicular macro-users. Using the stochastic geometry approach, a tractable model of the network is proposed. Based on the proposed model, integral expressions for CoMP-JT probability and coverage probability of non-vehicular macro user equipment are derived. Simulations verify the accuracy of the derived expressions. The results show that the probability for macro user equipment to be served with CoMP-JT is up to 70% when the intensity of MRs is ten times that of MBSs. This paper also includes a performance comparison among the analyzed scheme and related works. CoMP-JT with MRs provides better coverage performance for nearby macro user equipment. It can be found that the coverage gain of CoMP increases when the intensity of MRs increases within a certain range. Simulation results provide insights for practical system design in smart cities, such as the optimal MR intensity and the feasibility for opening access of MRs to macro user equipment.

URL الوصول: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::01d7f19db277984cec981a864706abe3
https://ieeexplore.ieee.org/document/7982594/

المؤلفون: Seyed Mohammad Azimi-Abarghouyi, Tommy Svensson, Masoumeh Nasiri-Kenari, Behrooz Makki, Mohsen Hejazi

المصدر: IEEE Transactions on Vehicular Technology. 65:8112-8129

مصطلحات موضوعية: Engineering, Computational complexity theory, Computer Networks and Communications, business.industry, Aerospace Engineering, 020302 automobile design & engineering, 020206 networking & telecommunications, 02 engineering and technology, Interference cancelation, law.invention, Low complexity, 0203 mechanical engineering, Relay, law, Robustness (computer science), Channel state information, Automotive Engineering, 0202 electrical engineering, electronic engineering, information engineering, Electronic engineering, Electrical and Electronic Engineering, business, Algorithm, Astrophysics::Galaxy Astrophysics, Computer Science::Information Theory, Communication channel

الوصف: This paper develops efficient compute-and-forward (CMF) schemes in multiuser multirelay networks. To solve the rank failure problem in CMF setups and to achieve full diversity of the network, we introduce two novel CMF methods, namely, extended CMF and successive CMF. The former, having low complexity, is based on recovering multiple equations at relays. The latter utilizes successive interference cancelation (SIC) to enhance system performance compared with the state-of-the-art schemes. Both methods can be utilized in a network with different number of users, relays, and relay antennas, with negligible feedback channels or signaling overhead. We derive new concise formulations and explicit framework for the successive CMF method, as well as an approach to reduce its computational complexity. Our theoretical analysis and computer simulations demonstrate the superior performance of our proposed CMF methods over the conventional schemes. Furthermore, based on our simulation results, the successive CMF method yields additional signal-to-noise ratio (SNR) gains and shows considerable robustness against channel estimation error (CEE), compared with the extended CMF method.

URL الوصول: https://explore.openaire.eu/search/publication?articleId=doi_________::d4c3cafd4294313de1b6a279c1fc61fe
https://doi.org/10.1109/tvt.2015.2506981

المؤلفون: Thomas Eriksson, Behrooz Makki, Tommy Svensson

المصدر: IEEE Transactions on Vehicular Technology. 65:2078-2096

مصطلحات موضوعية: FOS: Computer and information sciences, Computer Networks and Communications, Computer science, Computer Science - Information Theory, Aerospace Engineering, Hybrid automatic repeat request, Throughput, Data_CODINGANDINFORMATIONTHEORY, 02 engineering and technology, law.invention, 0203 mechanical engineering, Relay, law, Computer Science::Networking and Internet Architecture, 0202 electrical engineering, electronic engineering, information engineering, Fading, Electrical and Electronic Engineering, Throughput (business), Computer Science::Information Theory, business.industry, Information Theory (cs.IT), ComputerSystemsOrganization_COMPUTER-COMMUNICATIONNETWORKS, 020302 automobile design & engineering, 020206 networking & telecommunications, Outage probability, Power (physics), Constraint (information theory), Automotive Engineering, business, Communication channel, Computer network

الوصف: This paper investigates the performance of relay networks in the presence of hybrid automatic repeat request (ARQ) feedback and adaptive power allocation. The throughput and the outage probability of different hybrid ARQ protocols are studied for independent and spatially-correlated fading channels. The results are obtained for the cases where there is a sum power constraint on the source and the relay or when each of the source and the relay are power-limited individually. With adaptive power allocation, the results demonstrate the efficiency of relay-ARQ techniques in different conditions.
Accepted for publication in IEEE Trans. Veh. Technol. 2015

URL الوصول: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::78f75866e5e6e8f8489ca1b1e39f1f8a
https://doi.org/10.1109/tvt.2015.2424250

المؤلفون: Wei Yang, Agisilaos Papadogiannis, Yutao Sui, Tommy Svensson

المصدر: VTC Fall

مصطلحات موضوعية: Engineering, business.industry, Wireless network, Node (networking), ComputerSystemsOrganization_COMPUTER-COMMUNICATIONNETWORKS, 020302 automobile design & engineering, 020206 networking & telecommunications, Data_CODINGANDINFORMATIONTHEORY, 02 engineering and technology, 7. Clean energy, law.invention, Base station, 0203 mechanical engineering, Transmission (telecommunications), Wireless broadband, Relay, law, 11. Sustainability, 0202 electrical engineering, electronic engineering, information engineering, business, Computer network, Efficient energy use, Rayleigh fading

الوصف: In future wireless networks a significant number of wireless broadband users will be vehicular, i.e., they will be in public transportation vehicles like buses, trams or trains. In this paper, we show that the efficient use of relay nodes to serve vehicular users can greatly improve the energy efficiency of the network while maintaining the required quality-of-service (QoS). We consider vehicular users moving along a road within the coverage of a base station (BS). Communication can take place in a single-hop fashion (baseline case) or can be assisted by a single relay node (dual-hop), which can either be a fixed relay node (FRN) deployed at a specific position on the road or a moving relay node (MRN) mounted on top of the vehicle. We compare the required overall transmit energy for direct transmission, FRN and MRN assisted transmission in a noise limited system under Rayleigh fading while assuming an outage probability (OP) target. A lower bound is derived for the required energy of the FRN assisted transmission. It is shown that as the vehicular penetration loss (VPL) increases, both FRN and MRN assisted transmission can significantly lower the overall transmit energy compared to the conventional one-hop case. Moreover, transmission relying on an MRN outperforms the FRN assisted case when VPL is moderate to high.

URL الوصول: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::ed96a7bf7b93a161a09ed9851978d4eb

المؤلفون: Peter Fertl, Wanlu Sun, Zhe Ren, Tommy Svensson, Yutao Sui

المصدر: ICCVE

مصطلحات موضوعية: Engineering, business.industry, Quality of service, Radio equipment, ComputerSystemsOrganization_COMPUTER-COMMUNICATIONNETWORKS, Co-channel interference, 020206 networking & telecommunications, 020302 automobile design & engineering, 02 engineering and technology, law.invention, Base station, 0203 mechanical engineering, Transmission (telecommunications), Handover, User equipment, Relay, law, 0202 electrical engineering, electronic engineering, information engineering, business, Computer network

الوصف: In this paper, we investigate the power outage probability (OP) of a vehicular user equipment (VUE) device served by half-duplex decode-and-forward relay nodes (RNs) under co-channel interference. Both moving RNs (MRNs) and fixed RNs (FRNs) are studied, and compared with the baseline, base station (BS) to VUE direct transmission. In order to understand the benefit for vehicular users served by an RN, we consider practical channel models for different involved links as well as the impact of handover (HO) between the BS and the RNs. For an accurate comparison, we present a comprehensive framework to optimize the HO parameters, as well as we numerically optimize the FRN position which minimizes the average power OP at the VUE. FRN shows its advantage to serve its nearby VUEs. However, when vehicular penetration loss is moderate to high, MRN assisted transmission greatly outperforms transmission assisted by an FRN as well as direct transmission. Hence, the use of MRNs is very promising for improving the quality-of-service (QoS) of VUEs in future mobile communication systems.

URL الوصول: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::3007f65404bbd0b9d70916ae3dd8d29e

المؤلفون: Agisilaos Papadogiannis, Tommy Svensson, Wei Yang, Yutao Sui

المصدر: 2012 IEEE Globecom Workshops, GC Wkshps 2012; Anaheim, CA; United States; 3 December 2012 through 7 December 2012
GLOBECOM Workshops

مصطلحات موضوعية: Computer science, business.industry, Quality of service, Node (networking), ComputerSystemsOrganization_COMPUTER-COMMUNICATIONNETWORKS, Communication Systems, Co-channel interference, 020302 automobile design & engineering, 020206 networking & telecommunications, 02 engineering and technology, Data_CODINGANDINFORMATIONTHEORY, Interference (wave propagation), law.invention, 0203 mechanical engineering, Transmission (telecommunications), Relay, law, Performance comparison, 0202 electrical engineering, electronic engineering, information engineering, Electronic engineering, business, Computer network

الوصف: In this paper, we study and compare the outage probability (OP) of a vehicular user of dual-hop moving relay node (MRN) assisted transmission, dual-hop transmission assisted by a fixed relay node (FRN), as well as of the baseline single-hop direct transmission under of co-channel interference. For an accurate comparison, we numerically optimize the FRN position which minimizes the average vehicular user OP. When vehicular penetration loss is moderate to high, MRN assisted transmission is shown to greatly outperform transmission assisted by an FRN as well as direct transmission. Hence the use of MRNs is very promising for improving the quality-of-service of vehicular users for future mobile communication systems.

وصف الملف: application/pdf

URL الوصول: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::6ae5104d46b89f764d83df4d4e74aef4
https://research.chalmers.se/en/publication/171308

المؤلفون: Tommy Svensson, Yutao Sui, Agisilaos Papadogiannis

المصدر: IEEE Vehicular Technology Conference (15502252)
VTC Spring

مصطلحات موضوعية: Engineering, business.industry, Wireless network, Reliability (computer networking), Node (networking), ComputerSystemsOrganization_COMPUTER-COMMUNICATIONNETWORKS, 020302 automobile design & engineering, 020206 networking & telecommunications, 02 engineering and technology, Data_CODINGANDINFORMATIONTHEORY, Transmitter power output, law.invention, Fixed cell, 0203 mechanical engineering, Transmission (telecommunications), Relay, law, 11. Sustainability, 0202 electrical engineering, electronic engineering, information engineering, Electronic engineering, Telecommunications, business, Rayleigh fading

الوصف: In this paper we show the potential of moving relay nodes (MRNs), i.e., relays mounted on top of public transportation vehicles, to improve capacity, reliability and coverage for vehicular users in future wireless networks. To this end, we study and compare the performance of dual-hop MRN assisted transmission, dual-hop transmission assisted by a fixed relay node (FRN) deployed on the street, as well as of the baseline single-hop direct transmission. For an accurate comparison, we optimize the FRN position in terms of outage probability (OP). This position is a function of the pathloss, transmit power and vehicle penetration loss (VPL). The problem is investigated for Rayleigh fading under a fixed cell coverage. When VPL is moderate to high, MRN assisted transmission greatly outperforms transmission assisted by an FRN as well as direct transmission, hence it is very promising for future wireless systems.

وصف الملف: application/pdf

URL الوصول: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::cc54f0f687d9783150f121e644f8df63
https://research.chalmers.se/en/publication/153460