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Hoang, Le-Nam
Publications (3 of 3) Show all publications
Dao, V.-L., Hoang, L.-N., Girs, S. & Uhlemann, E. (2021). Defeating Jamming Using Outage Performance Aware Joint Power Allocation and Access Point Placement in Uplink Pairwise NOMA. IEEE Open Journal of the Communications Society, 2, 1957-1979
Open this publication in new window or tab >>Defeating Jamming Using Outage Performance Aware Joint Power Allocation and Access Point Placement in Uplink Pairwise NOMA
2021 (English)In: IEEE Open Journal of the Communications Society, E-ISSN 2644-125X, Vol. 2, p. 1957-1979Article in journal (Refereed) Published
Abstract [en]

In this paper, an uplink pairwise Non-Orthogonal Multiple Access (NOMA) scenario using a mobile access point (AP) or an unmanned aerial vehicle in the presence of a jamming attack is considered. To mitigate the influence of the jamming attack, a joint power allocation and AP placement design is proposed. Accordingly, closed-form expressions of the overall outage probability (OOP) and the individual outage probability (TOP) considering imperfect channel state information for each of the source nodes the AP serves, are derived over Nakagami-m fading channels using dynamic decoding order and fixed pairwise power allocation. We conduct an investigation of the effect of different parameters such as power allocation, source node placements, AP placement, target rates, and jammer location on the OOP and the IOP performance. By adapting the power allocation and the AP placement to the jamming attack, the communication reliability can be increased significantly compared to neglecting the presence of the jammer or treating the jammer as noise. Since the malicious jammer and the AP have conflicting interests in terms of communication reliability, we formulate a non-cooperative game for the two players considering their positions and the power allocation of the NOMA nodes as their strategies and the OOP as utility function. We propose using hybrid simulated annealing - greedy algorithms to address the joint power allocation and AP placement problem for the cases of both a fixed and a mobile jammer. Finally, the Nash equilibrium points are obtained and then the UAV goes directly to this position and keeps staying there to save power consumption.

National Category
Telecommunications
Identifiers
urn:nbn:se:mdh:diva-55890 (URN)10.1109/OJCOMS.2021.3103540 (DOI)000692134000002 ()2-s2.0-85127267538 (Scopus ID)
Available from: 2021-09-16 Created: 2021-09-16 Last updated: 2024-01-23Bibliographically approved
Dao, V.-L., Hoang, L.-N., Girs, S. & Uhlemann, E. (2020). Outage Performance of Pairwise NOMA Allowing a Dynamic Decoding Order and Optimal Pairs of Power Levels. IEEE Open Journal of the Communications Society, 1, 1886-1906
Open this publication in new window or tab >>Outage Performance of Pairwise NOMA Allowing a Dynamic Decoding Order and Optimal Pairs of Power Levels
2020 (English)In: IEEE Open Journal of the Communications Society, E-ISSN 2644-125X, Vol. 1, p. 1886-1906Article in journal (Refereed) Published
Abstract [en]

In this article, we evaluate the overall outage probability (OOP) of pairwise Non-orthogonal Multiple Access (NOMA) for both uplink and downlink. We also propose a dynamic decoding order (DDO) together with a fixed pairwise power allocation (FPPA) scheme, in which the optimal decoding order is decided based on the instantaneous channel gains, and thereafter, a pair of power levels is assigned in accordance with the selected decoding order. Exact closed-form expressions of the OOPs for both uplink and downlink pairwise NOMA considering all proposed decoding orders over Nakagami- m fading are derived. Further, we find the optimal fixed power levels for different power allocation strategies so that the OOPs are minimized. Moreover, we investigate the influence of the distances between the source nodes and the access point (AP), the target transfer rates and the path-loss exponents on the OOPs for all cases of decoding orders. In addition, we benchmark our proposed DDO against other decoding orders in terms of the OOP. The results show that assigning optimal fixed power levels which takes the instantaneous decoding order into account not only improves the communication reliability, but also reduces the complexity and computational load at the AP.

Place, publisher, year, edition, pages
Sweden: IEEE OJCOMS, 2020
Keywords
Overall outage probability, pairwise NOMA, dynamic decoding order, optimal power allocation, uplink/downlink NOMA
National Category
Computer Systems
Identifiers
urn:nbn:se:mdh:diva-53953 (URN)10.1109/OJCOMS.2020.3039536 (DOI)000723372400126 ()2-s2.0-85119495170 (Scopus ID)
Projects
Future factories in the CloudFORA - Fog Computing for Robotics and Industrial Automation
Available from: 2021-04-22 Created: 2021-04-22 Last updated: 2023-09-06Bibliographically approved
Hoang, L.-N., Uhlemann, E. & Jonsson, M. (2019). Relay Grouping to Guarantee Timeliness and Reliability in Wireless Networks. IEEE Communications Letters, 23(9), 1661-1664, Article ID 8737952.
Open this publication in new window or tab >>Relay Grouping to Guarantee Timeliness and Reliability in Wireless Networks
2019 (English)In: IEEE Communications Letters, ISSN 1089-7798, E-ISSN 1558-2558, Vol. 23, no 9, p. 1661-1664, article id 8737952Article in journal (Refereed) Published
Abstract [en]

Relaying can increase reliability, range, or throughput. In many cyber-physical systems (CPS), relaying is used to maximize reliability before a given deadline. Since concurrent transmissions are not supported by most CPS, time-division multiple access (TDMA) is typically used. However, a major drawback of relaying in TDMA is that pre-allocated time-slots are wasted if their respective transmitters do not have any correctly received packet to relay. Therefore, in this letter, we propose a novel relay grouping scheme to overcome this drawback. Numerical results show that the proposed scheme significantly enhances the reliability while guaranteeing the deadline for each message. 

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers Inc., 2019
Keywords
industrial communication, multi-access communication, Relay networks, Embedded systems, Reliability, Wireless networks, Concurrent transmission, Cyber-physical systems (CPS), Industrial communications, Multi-access communications, Numerical results, Relay network, Time division multiple accesses (TDMA), Timeliness and reliability, Time division multiple access
National Category
Telecommunications Communication Systems Computer Engineering
Identifiers
urn:nbn:se:mdh:diva-45316 (URN)10.1109/LCOMM.2019.2923406 (DOI)000485733200048 ()2-s2.0-85072257501 (Scopus ID)
Available from: 2019-09-26 Created: 2019-09-26 Last updated: 2019-10-03Bibliographically approved
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