Abstract
Nonorthogonal multiple access (NOMA) significantly improves the connectivity opportunities and enhances the spectrum efficiency (SE) in the fifth generation and beyond (B5G) wireless communications. Meanwhile, emerging B5G services demand for higher SE in the NOMA-based wireless communications. However, traditional ground-to-ground (G2G) communications are hard to satisfy these demands, especially for the cellular uplinks. To solve these challenges, this article proposes a multiple unmanned-aerial-vehicles (UAVs)-aided uplink NOMA method. In detail, multiple hovering UAVs relay data for a half of ground users (GUs) and share the spectrums with the other GUs that communicate with the base station (BS) directly. Furthermore, this article proposes a K-means clustering-based UAV deployment scheme and location-based user pairing (UP) scheme to optimize the transceiver association for the multiple UAVs-aided NOMA uplinks. Finally, a sum power minimization-based resource allocation problem is formulated with the lowest Quality-of-Service (QoS) constraints. We solve it with the message-passing algorithm and evaluate the superior performances of the proposed scheduling and paring schemes on SE and energy efficiency (EE). Extensive simulations are conducted to compare the performances of the proposed schemes with those of the single UAV-aided NOMA uplinks, G2G-based NOMA uplinks, and the proposed multiple UAVs-aided uplinks with a facility location framework-based UAV deployment. Simulation results demonstrate that the proposed multiple UAVs deployment and UP-based NOMA scheme significantly improves the EE and the SE of the cellular uplinks at the cost of only a little relaying power consumption of UAVs.
Highlights
In single unmanned aerial vehicles (UAVs) based cellular non-orthogonal multiple access (NOMA) scheme, the UAV is placed above the base station (BS) with an initial height
The first half ground users (GUs) have higher Ad, they will be assigned to communicate with UAVs
This paper proposed a multiple UAVs aided uplink NOMA technology to improve the energy efficiency and spectral efficiency of the GUs’ uplink transmission in cellular networks
Summary
Ubiquitous connectivity with ultra-high spectrum efficiency and system throughput is one of the crucial requirements for. Through significantly improving the connectivity and spectrum efficiency [8]–[12], non-orthogonal multiple access (NOMA) has become a promising solution for the B5G communications. In the NOMA aided systems, multiple users with different channel conditions are multiplexed in power domain and served on the same sub-channels simultaneously. In recent years, many other promising techniques have been widely researched through combining NOMA. Multiple input multiple-output based NOMA techniques were investigated in [14], [15]. Dynamic resource allocation schemes for improving performances of the NOMA based networks were explored in [16]–[18]. Applying NOMA to heterogeneous networks were discussed in [21]–[23]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
