TY - JOUR
T1 - Robust Non-Orthogonal Multiple Access for Aerial and Ground Users
AU - New, Wee Kiat
AU - Leow, Chee Yen
AU - Navaie, Keivan
AU - Ding, Zhiguo
N1 - Funding Information:
Manuscript received July 27, 2019; revised November 25, 2019 and January 29, 2020; accepted April 5, 2020. Date of publication April 17, 2020; date of current version July 10, 2020. This work was supported in part by H2020-MSCA-RISE-2015 under Grant 690750, in part by the Ministry of Higher Education Malaysia and Universiti Teknologi Malaysia under Grant 4J416, Grant 08G83, Grant 09G15, Grant 19H58 and Grant 04G37. The work of Zhiguo Ding was supported by UK Engineering and Physical Sciences Research Council (EPSRC) under Grant EP/P009719/2. The associate editor coordinating the review of this article and approving it for publication was X Yuan. (Corresponding author: Chee Yen Leow.) Wee Kiat New and Chee Yen Leow are with the Wireless Communication Centre, School of Electrical Engineering, Faculty of Engineering, Universiti Teknologi Malaysia, Skudai 81310, Malaysia (e-mail: [email protected]; [email protected]).
Publisher Copyright:
© 2002-2012 IEEE.
PY - 2020/7
Y1 - 2020/7
N2 - In this paper, we consider a downlink wireless communication system with the co-existence of ground user (GU) and mobile aerial user (AU). Existing solutions rely on orthogonal multiple access (OMA) to support these users, however, OMA is unable to provide the best rate and outage performance because its spectral efficiency is limited by the users' channel conditions and rate requirements. Thus, we propose an aerial-ground non-orthogonal multiple access (AG-NOMA) scheme that pairs the GU and AU for data and control links, respectively. Unlike terrestrial non-orthgonal multiple access (NOMA), the key idea of AG-NOMA is to exploit the asymmetric features of the channels and rate demands of the GU and AU in the downlink communication. Based on these opportunities, we investigate the maximum achievable GU rate over a time-varying wireless channel while satisfying the AU Quality-of-Service (QoS) requirement with perfect and partial channel state information (CSI). For perfect CSI, we derive the optimal successive interference cancellation (SIC) policy, power allocation, GU rate, and feasibility conditions in closed-form expressions. For partial CSI, we also derive the suboptimal SIC policy and power allocation in closed-form expressions, and further discussed a tradeoff between the achievable rate and reliability. This tradeoff depends on the system parameters, and thus we have suggested some appropriate parameters based on theoretical support and standard requirements to strike a balance between rate and reliability. Our simulation results show that AG-NOMA scheme with perfect and partial CSI can achieve up to +99% GU rate-improvement as compared to OMA and provide a more sustainable rate-improvement and/or lower outage probability than terrestrial NOMA scheme.
AB - In this paper, we consider a downlink wireless communication system with the co-existence of ground user (GU) and mobile aerial user (AU). Existing solutions rely on orthogonal multiple access (OMA) to support these users, however, OMA is unable to provide the best rate and outage performance because its spectral efficiency is limited by the users' channel conditions and rate requirements. Thus, we propose an aerial-ground non-orthogonal multiple access (AG-NOMA) scheme that pairs the GU and AU for data and control links, respectively. Unlike terrestrial non-orthgonal multiple access (NOMA), the key idea of AG-NOMA is to exploit the asymmetric features of the channels and rate demands of the GU and AU in the downlink communication. Based on these opportunities, we investigate the maximum achievable GU rate over a time-varying wireless channel while satisfying the AU Quality-of-Service (QoS) requirement with perfect and partial channel state information (CSI). For perfect CSI, we derive the optimal successive interference cancellation (SIC) policy, power allocation, GU rate, and feasibility conditions in closed-form expressions. For partial CSI, we also derive the suboptimal SIC policy and power allocation in closed-form expressions, and further discussed a tradeoff between the achievable rate and reliability. This tradeoff depends on the system parameters, and thus we have suggested some appropriate parameters based on theoretical support and standard requirements to strike a balance between rate and reliability. Our simulation results show that AG-NOMA scheme with perfect and partial CSI can achieve up to +99% GU rate-improvement as compared to OMA and provide a more sustainable rate-improvement and/or lower outage probability than terrestrial NOMA scheme.
KW - cellular-connected UAV
KW - Non-orthogonal multiple access
KW - optimal power allocation
KW - optimal SIC policy
UR - http://www.scopus.com/inward/record.url?scp=85088395392&partnerID=8YFLogxK
U2 - 10.1109/TWC.2020.2987315
DO - 10.1109/TWC.2020.2987315
M3 - Article
AN - SCOPUS:85088395392
SN - 1536-1276
VL - 19
SP - 4793
EP - 4805
JO - IEEE Transactions on Wireless Communications
JF - IEEE Transactions on Wireless Communications
IS - 7
M1 - 9070200
ER -