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Kim, D., Yang, Y., Sung, K. W. & Kang, J. (2018). Cooperation Strategies for Partly Wireless C-RAN. IEEE Communications Letters, 22(6), 1248-1251
Öppna denna publikation i ny flik eller fönster >>Cooperation Strategies for Partly Wireless C-RAN
2018 (Engelska)Ingår i: IEEE Communications Letters, ISSN 1089-7798, E-ISSN 1558-2558, Vol. 22, nr 6, s. 1248-1251Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

This letter presents a variant of cloud radio access network (C-RAN) architecture, which we term partly wireless C-RAN (PW-CRAN). It is characterized by extra radio nodes connected through the existing remote radio heads. Because of the newly connected nodes and the consequent additional delay, the operation of PW-CRAN requires different approaches compared with that of the typical C-RAN. Specifically, the effect of delayed channel state information on the suitability of network cooperation should be identified. To tackle this problem, we introduce two representative cooperation strategies and evaluate the performance with regard to the delay via simulations. Numerical results suggest that it is better to exclude the extra nodes from cooperation if they incur excess delay. Furthermore, whether the delay is deemed excessive depends on the interference environment. Hence, we provide quantified guidelines on the cooperation strategy of PW-CRAN.

Ort, förlag, år, upplaga, sidor
IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2018
Nyckelord
Cloud radio access network, cooperation strategy, fronthaul link, delay, imperfect channel state information
Nationell ämneskategori
Elektroteknik och elektronik Kommunikationssystem
Identifikatorer
urn:nbn:se:kth:diva-231721 (URN)10.1109/LCOMM.2018.2807814 (DOI)000435175800035 ()2-s2.0-85042172488 (Scopus ID)
Anmärkning

QC 20180815

Tillgänglig från: 2018-08-15 Skapad: 2018-08-15 Senast uppdaterad: 2018-11-20Bibliografiskt granskad
Shokri-Ghadikolaei, H., Yang, Y., Petrova, M., Sung, K. W. & Fischione, C. (2018). Fast and Reliable Initial Cell-search for mmWave Networks. In: : . Paper presented at 2nd ACM Workshop on Millimeter-Wave Networks and Sensing Systems 2018 (mmNets’18) (pp. 57-62). Association for Computing Machinery (ACM)
Öppna denna publikation i ny flik eller fönster >>Fast and Reliable Initial Cell-search for mmWave Networks
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2018 (Engelska)Konferensbidrag, Publicerat paper (Refereegranskat)
Abstract [en]

In millimeter-wave wireless networks, the use of narrow beams, required to compensate for the severe path-loss, complicates the cell-discovery and initial access. In this paper, we investigate the feasibility of random beam forming and enhanced exhaustive search for cell-discovery by analyzing the latency and detection failure probability in the control-plane and the user throughput in the data-plane. We show that, under realistic propagation model and antenna patterns, both approaches are suitable for 3GPP New Radio cellular networks. The performance gain, compared to the heavily used exhaustive and iterative search schemes, is more prominent in dense networks and large antenna regimes and can be further improved by optimizing the beam forming code-books.

Ort, förlag, år, upplaga, sidor
Association for Computing Machinery (ACM), 2018
Nationell ämneskategori
Kommunikationssystem
Identifikatorer
urn:nbn:se:kth:diva-239140 (URN)10.1145/3264492.3264502 (DOI)000480467200011 ()2-s2.0-85061490095 (Scopus ID)978-1-4503-5928-3 (ISBN)
Konferens
2nd ACM Workshop on Millimeter-Wave Networks and Sensing Systems 2018 (mmNets’18)
Anmärkning

QC 20181119

Tillgänglig från: 2018-11-16 Skapad: 2018-11-16 Senast uppdaterad: 2019-09-03Bibliografiskt granskad
Kim, J., Park, J., Kim, S., Kim, S.-L., Sung, K. W. & Kim, K. S. (2018). Millimeter-Wave Interference Avoidance via Building-Aware Associations. IEEE Access, 6, 10618-10634
Öppna denna publikation i ny flik eller fönster >>Millimeter-Wave Interference Avoidance via Building-Aware Associations
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2018 (Engelska)Ingår i: IEEE Access, E-ISSN 2169-3536, Vol. 6, s. 10618-10634Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

Signal occlusion by building blockages is a double-edged sword for the performance of millimeter-wave (mmW) communication networks. Buildings may dominantly attenuate the useful signals, especially when mmW base stations (BSs) are sparsely deployed compared with the building density. In the opposite BS deployment, buildings can block the undesired interference. To enjoy only the benefit, we propose a building-aware association scheme that adjusts the directional BS association bias of the user equipments (UEs), based on a given building density and the concentration of UE locations around the buildings. The association of each BS can thereby be biased: 1) toward the UEs located against buildings for avoiding interference to other UEs or 2) toward the UEs providing their maximum reference signal received powers. The proposed association scheme is optimized to maximize the downlink average data rate derived by stochastic geometry. Its effectiveness is validated by simulation using real building statistics.

Ort, förlag, år, upplaga, sidor
IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2018
Nyckelord
Millimeter-wave communications, building blockages, base station association, load balancing, average data rate, stochastic geometry
Nationell ämneskategori
Elektroteknik och elektronik
Identifikatorer
urn:nbn:se:kth:diva-225756 (URN)10.1109/ACCESS.2018.2800682 (DOI)000427899700001 ()2-s2.0-85041518608 (Scopus ID)
Anmärkning

QC 20180411

Tillgänglig från: 2018-04-11 Skapad: 2018-04-11 Senast uppdaterad: 2018-04-11Bibliografiskt granskad
Yang, Y., Hossein, S.-G., Fischione, C., Petrova, M. & Sung, K. W. (2018). Reducing Initial Cell-search Latency in mmWave Networks. In: INFOCOM 2018 - IEEE Conference on Computer Communications Workshops: . Paper presented at IEEE INFOCOM 2018 - IEEE Conference on Computer Communications Workshops (INFOCOM WKSHPS). IEEE conference proceedings
Öppna denna publikation i ny flik eller fönster >>Reducing Initial Cell-search Latency in mmWave Networks
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2018 (Engelska)Ingår i: INFOCOM 2018 - IEEE Conference on Computer Communications Workshops, IEEE conference proceedings, 2018Konferensbidrag, Publicerat paper (Refereegranskat)
Abstract [en]

Millimeter-wave (mmWave) networks rely on directional transmissions, in both control plane and data plane, to overcome severe path-loss. Nevertheless, the use of narrow beams complicates the initial cell-search procedure where we lack sufficient information for beamforming. In this paper, we investigate the feasibility of random beamforming for cell-search. We develop a stochastic geometry framework to analyze the performance in terms of failure probability and expected latency of cell-search. Meanwhile, we compare our results with the naive, but heavily used, exhaustive search scheme. Numerical results show that, for a given discovery failure probability, random beamforming can substantially reduce the latency of exhaustive search, especially in dense networks. Our work demonstrates that developing complex cell-discovery algorithms may be unnecessary in dense mmWave networks and thus shed new lights on mmWave system design.

Ort, förlag, år, upplaga, sidor
IEEE conference proceedings, 2018
Nationell ämneskategori
Kommunikationssystem
Identifikatorer
urn:nbn:se:kth:diva-239139 (URN)10.1109/INFCOMW.2018.8406924 (DOI)000450157700178 ()2-s2.0-85050687161 (Scopus ID)
Konferens
IEEE INFOCOM 2018 - IEEE Conference on Computer Communications Workshops (INFOCOM WKSHPS)
Anmärkning

QC 20181120

Tillgänglig från: 2018-11-16 Skapad: 2018-11-16 Senast uppdaterad: 2019-04-15Bibliografiskt granskad
Čelik, H. & Sung, K. W. (2018). Scalable Resource Allocation for Dynamic TDD with Traffic and Propagation Awareness. Paper presented at Wireless Communications and Networking Conference (WCNC), 2018 IEEE.
Öppna denna publikation i ny flik eller fönster >>Scalable Resource Allocation for Dynamic TDD with Traffic and Propagation Awareness
2018 (Engelska)Manuskript (preprint) (Övrigt vetenskapligt)
Nationell ämneskategori
Elektroteknik och elektronik
Identifikatorer
urn:nbn:se:kth:diva-214773 (URN)
Konferens
Wireless Communications and Networking Conference (WCNC), 2018 IEEE
Anmärkning

QC 20170922

Tillgänglig från: 2017-09-20 Skapad: 2017-09-20 Senast uppdaterad: 2019-01-17Bibliografiskt granskad
Čelik, H. & Sung, K. W. (2018). Scalable Resource Allocation for Dynamic TDD with Traffic and Propagation Awareness. In: 2018 IEEE WIRELESS COMMUNICATIONS AND NETWORKING CONFERENCE (WCNC): . Paper presented at IEEE Wireless Communications and Networking Conference (WCNC), APR 15-18, 2018, Barcelona, SPAIN. IEEE
Öppna denna publikation i ny flik eller fönster >>Scalable Resource Allocation for Dynamic TDD with Traffic and Propagation Awareness
2018 (Engelska)Ingår i: 2018 IEEE WIRELESS COMMUNICATIONS AND NETWORKING CONFERENCE (WCNC), IEEE , 2018Konferensbidrag, Publicerat paper (Refereegranskat)
Abstract [en]

This paper presents a scalable scheduler for dynamic TDD systems in ultra-dense indoor deployments applicable to diverse traffic and radio propagation conditions. To minimize signalling for the channel estimation and feedback, the proposed scheduler employs offline BS-to-BS measurements to approximate the real interference for different traffic conditions. Thus, no CSI is required once the network is online. Furthermore, we show that signalling can be further reduced by considering only meaningful interferers above a received power threshold for the traffic information exchange. To perform the scheduling, a function that maps interference into individual BS activation probabilities is also introduced. Results show that the proposed scheme performs reasonably well in high interference situations compared to comparable scalable schedulers, and optimally when interference is low, both in average and 5th percentile sense.

Ort, förlag, år, upplaga, sidor
IEEE, 2018
Serie
IEEE Wireless Communications and Networking Conference, ISSN 1525-3511
Nyckelord
Dynamic MD, ultra-dense network, scalability
Nationell ämneskategori
Telekommunikation
Identifikatorer
urn:nbn:se:kth:diva-232289 (URN)000435542401101 ()2-s2.0-85049218813 (Scopus ID)978-1-5386-1734-2 (ISBN)
Konferens
IEEE Wireless Communications and Networking Conference (WCNC), APR 15-18, 2018, Barcelona, SPAIN
Anmärkning

QC 20180718

Tillgänglig från: 2018-07-18 Skapad: 2018-07-18 Senast uppdaterad: 2019-01-11Bibliografiskt granskad
Gimenez, J. J., Sung, K. W. & Gomez-Barquero, D. (2018). Semianalytical Approach to the PDF of SINR in HPHT and LPLT Single-Frequency Networks. IEEE Transactions on Vehicular Technology, 67(5), 4173-4181
Öppna denna publikation i ny flik eller fönster >>Semianalytical Approach to the PDF of SINR in HPHT and LPLT Single-Frequency Networks
2018 (Engelska)Ingår i: IEEE Transactions on Vehicular Technology, ISSN 0018-9545, E-ISSN 1939-9359, Vol. 67, nr 5, s. 4173-4181Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

Single-frequency networks (SFN) are widely adopted in terrestrial broadcast networks based on high-power high-tower (HPHT) deployments. The mobile broadcasting standard Evolved Multimedia Broadcast Multicast Service (eMBMS) has been enhanced in Release 14 to enable SFN operation with larger CP duration which may allow for the deployment of large area SFNs and even the combined operation between HPHT and low-power low-tower (LPLT) cellular stations. The knowledge of the signal-to-interference-plus-noise ratio (SINR) distribution over an SFN area may facilitate the selection of transmission parameters according to the network topology. This paper presents a semianalytical method for the calculation of the SINR distribution in SFNs with low computational complexity compared to Monte Carlo simulations. The method, which builds on previous work developed for cellular communications, is applied to HPHT+LPLT SFNs and evaluated against different transmission and network parameters.

Ort, förlag, år, upplaga, sidor
Institute of Electrical and Electronics Engineers (IEEE), 2018
Nyckelord
Single frequency network (SFN), network planning, low-power low-tower (LPLT), high-power high-tower (HPHT), cyclic prefix
Nationell ämneskategori
Kommunikationssystem
Identifikatorer
urn:nbn:se:kth:diva-229024 (URN)10.1109/TVT.2018.2791347 (DOI)000432310500038 ()2-s2.0-85040545167 (Scopus ID)
Anmärkning

QC 20180531

Tillgänglig från: 2018-05-31 Skapad: 2018-05-31 Senast uppdaterad: 2018-05-31Bibliografiskt granskad
Al-Saadeh, O. & Sung, K. W. (2017). A performance comparison of in-band full duplex and dynamic TDD for 5G indoor wireless networks. EURASIP Journal on Wireless Communications and Networking, Article ID 50.
Öppna denna publikation i ny flik eller fönster >>A performance comparison of in-band full duplex and dynamic TDD for 5G indoor wireless networks
2017 (Engelska)Ingår i: EURASIP Journal on Wireless Communications and Networking, ISSN 1687-1472, E-ISSN 1687-1499, artikel-id 50Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

In-band full duplex has emerged as a solution for high data rate and low access delay for 5G wireless networks after its feasibility has been demonstrated. However, the impact of the in-band full duplex on the system-level performance of multi-cell wireless networks has not been investigated thoroughly. In this paper, we conduct an extensive simulation study to investigate the performance of in-band full duplex for indoor 5G small cell wireless networks. Particularly, we compare the in-band full duplex with static and dynamic time division duplexing schemes which require much less hardware complexity. We examine the effects of beamforming and interference cancellation under various traffic demands and asymmetry situations in the performance comparison. Our objective is to identify under which condition and with which technology support the in-band full duplex becomes advantageous over the simpler duplexing schemes. Numerical results indicate that for highly utilized wireless networks, in-band full duplex should be combined with interference cancellation and beamforming in order to achieve a performance gain over traditional duplexing schemes. Only then in-band full duplex is considered to be advantageous at any number of active mobile stations in the network and any downlink to uplink traffic proportion. Our results also suggest that in order to achieve a performance gain with the in-band full duplex in both links, the transmit power of the access points and the mobile stations should be comparable.

Ort, förlag, år, upplaga, sidor
Springer, 2017
Nyckelord
Wireless networks, In-band full duplex, Static time division duplexing, Dynamic time division duplexing, Interference mitigation techniques, Small cell, 5G, mmWave bands, Beamforming, Interference cancellation
Nationell ämneskategori
Telekommunikation
Identifikatorer
urn:nbn:se:kth:diva-205459 (URN)10.1186/s13638-017-0833-3 (DOI)000397592000002 ()2-s2.0-85015786440 (Scopus ID)
Anmärkning

QC 20170522

Tillgänglig från: 2017-05-22 Skapad: 2017-05-22 Senast uppdaterad: 2017-05-22Bibliografiskt granskad
Yang, Y., Sung, K. W., Park, J., Kim, S.-L. -. & Kim, K. S. (2017). Cooperative transmissions in ultra-dense networks under a bounded dual-slope path loss model. In: 2017 European Conference on Networks and Communications (EuCNC): . Paper presented at 2017 European Conference on Networks and Communications, EuCNC 2017, Oulu, Finland, 12 June 2017 through 15 June 2017. Institute of Electrical and Electronics Engineers (IEEE)
Öppna denna publikation i ny flik eller fönster >>Cooperative transmissions in ultra-dense networks under a bounded dual-slope path loss model
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2017 (Engelska)Ingår i: 2017 European Conference on Networks and Communications (EuCNC), Institute of Electrical and Electronics Engineers (IEEE), 2017Konferensbidrag, Publicerat paper (Refereegranskat)
Abstract [en]

In an ultra-dense network (UDN) where there are more base stations (BSs) than active users, it is possible that many BSs are instantaneously left idle. Thus, how to utilize these dormant BSs by means of cooperative transmission is an interesting question. In this paper, we investigate the performance of a UDN with two types of cooperation schemes: Non-coherent joint transmission (JT) without channel state information (CSI) and coherent JT with full CSI knowledge. We consider a bounded dual-slope path loss model to describe UDN environments where a user has several BSs in the near-field and the rest in the far-field. Numerical results show that non-coherent JT cannot improve the user spectral efficiency (SE) due to the simultaneous increment in signal and interference powers. For coherent JT, the achievable SE gain depends on the range of near-field, the relative densities of BSs and users, and the CSI accuracy. Finally, we assess the energy efficiency (EE) of cooperation in UDN. Despite costing extra energy consumption, cooperation can still improve EE under certain conditions.

Ort, förlag, år, upplaga, sidor
Institute of Electrical and Electronics Engineers (IEEE), 2017
Nyckelord
bounded path loss model, cooperative transmissions, multi-slope path loss model, Ultra-dense networks
Nationell ämneskategori
Kommunikationssystem
Identifikatorer
urn:nbn:se:kth:diva-221121 (URN)10.1109/EuCNC.2017.7980732 (DOI)2-s2.0-85039946526 (Scopus ID)9781538638736 (ISBN)
Konferens
2017 European Conference on Networks and Communications, EuCNC 2017, Oulu, Finland, 12 June 2017 through 15 June 2017
Anmärkning

QC 20180115

Tillgänglig från: 2018-01-15 Skapad: 2018-01-15 Senast uppdaterad: 2018-11-20Bibliografiskt granskad
Čelik, H. & Sung, K. W. (2017). Joint transmission with dummy symbols for dynamic TDD in ultra-dense deployments. In: EuCNC 2017 - European Conference on Networks and Communications: . Paper presented at 2017 European Conference on Networks and Communications, EuCNC 2017, Oulu, Finland, 12 June 2017 through 15 June 2017. IEEE, Article ID 7980720.
Öppna denna publikation i ny flik eller fönster >>Joint transmission with dummy symbols for dynamic TDD in ultra-dense deployments
2017 (Engelska)Ingår i: EuCNC 2017 - European Conference on Networks and Communications, IEEE, 2017, artikel-id 7980720Konferensbidrag, Publicerat paper (Refereegranskat)
Abstract [en]

Dynamic time-division duplexing (TDD) is considered a promising solution to deal with fast-varying traffic often found in ultra-densely deployed networks. At the same time, it generates more interference which may degrade the performance of some user equipment (UE). When base station (BS) utilization is low, some BSs may not have an UE to serve. Rather than going into sleep mode, the idle BSs can help nearby UEs using joint transmission. To deal with BS-to-BS interference, we propose using joint transmission with dummy symbols where uplink BSs serving uplink UEs participate in the precoding. Since BSs are not aware of the uplink symbols beforehand, any symbols with zero power can be transmitted instead to null the BS-to-BS interference. Numerical results show significant performance gains for uplink and downlink at low and medium utilization. By varying the number of participating uplink BSs in the precoding, we also show that it is possible to successfully trade performance in the two directions.

Ort, förlag, år, upplaga, sidor
IEEE, 2017
Nationell ämneskategori
Elektroteknik och elektronik
Identifikatorer
urn:nbn:se:kth:diva-214772 (URN)10.1109/EuCNC.2017.7980720 (DOI)2-s2.0-85039925551 (Scopus ID)9781538638736 (ISBN)
Konferens
2017 European Conference on Networks and Communications, EuCNC 2017, Oulu, Finland, 12 June 2017 through 15 June 2017
Anmärkning

QC 20170922

Tillgänglig från: 2017-09-20 Skapad: 2017-09-20 Senast uppdaterad: 2019-01-11Bibliografiskt granskad
Organisationer
Identifikatorer
ORCID-id: ORCID iD iconorcid.org/0000-0001-7642-3067

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