scholarly journals Joint Channel Allocation and Power Control for Uplink NOMA-Assisted Multi-UAV Networks

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Shaojie Wen ◽  
Lianbing Deng ◽  
Zengliang Liu

The explosive growth of data leads to that the traditional wireless networks cannot enable various quality of service (QoS) communication for cellular-connected multi-UAV (unmanned aerial vehicle) networks. To overcome this obstacle, we solve the joint optimization problem of channel allocation and power control for uplink NOMA-assisted multi-UAV networks. Firstly, we design a mixed integer nonlinear programming framework, where the channel gains are characterized with integral form in time interval and sorted in nondescending order as the priority index of the decoded signal. In order to propose a feasible algorithm, the initial power levels of UAVs are obtained and integrated into the original problem which is reduced to integer programming problem. Then, the UAVs whose channel gain differences satisfy the constraints will be divided into a group to share the same channel, while the initial power levels of UAVs are adjusted to get a more satisfactory initial solution for power control. Combining the solution of channel allocation and the initial power levels, we solve power control problem with asynchronous update mechanism until the power levels of UAVs remain unchanged. Finally, we propose a channel allocation algorithm and a power control algorithm with the asynchronous optimization mechanism, respectively. Simulation results show that the proposed algorithms can effectively improve the network performance in terms of the aggregated rate.

Sensors ◽  
2020 ◽  
Vol 20 (11) ◽  
pp. 3285 ◽  
Author(s):  
Li Zhou ◽  
Yucheng Wu ◽  
Haifei Yu

Energy efficiency (EE) is a critical performance indicator for the device-to-device (D2D) communication underlaying cellular networks due to limited battery capacity and serious interference between user equipment. In this study, we proposed a power control and channel allocation scheme for the EE maximization of the D2D pairs, while jointly reusing uplink–downlink resources and guaranteeing the cellular users’ (CUs) quality of service (QoS). The formulated problem was a mixed-integer nonlinear programming (MINLP) problem, which is generally an unsolved non-deterministic polynomial-time hardness (NP-hard) problem within polynomial time. To make it tractable to solve, the original problem was divided into two sub-problems: power control and channel allocation. A power control algorithm based on the Lambert W function was proposed to maximize the EE of the individual D2D pair. Assigning either an uplink or downlink resource to reuse, the EE of each D2D pair was calculated using the power control results. A channel allocation scheme based on the Kuhn–Munkres algorithm utilized the EE weights to optimize the overall EE of the D2D pairs. The simulation results verified the theoretical analysis and proved that the proposed algorithm could remarkably improve the EE of D2D pairs while guaranteeing the QoS of the CUs.


2012 ◽  
Vol 562-564 ◽  
pp. 2049-2052
Author(s):  
Zhi Hua Zheng

Asymmetrical traffic service requirements between uplink (UL) and downlink (DL) will cause serious inter-cell interference in TDD/CDMA system. In this paper, an efficient power control algorithm with dynamic channel allocation (PC/DCA) is investigated, which is based on the average power control algorithms. In the uplink and downlink, PC/DCA scheme is addressed with channel reservation to resolve the interference between base-stations. Simulation results show that the performance of the PC/DCA scheme is improved 20% than that of the traditional DCA schemes for asymmetrical traffic service.


2020 ◽  
Vol 10 (7) ◽  
pp. 2446
Author(s):  
Wenying Gu ◽  
Qi Zhu

In mobile communication systems, device-to-device (D2D) communication and nonorthogonal multiple access (NOMA) are effective ways to improve spectrum efficiency and system throughput. In the NOMA-based D2D system, social relationship among D2D users is introduced to form D2D clusters, and NOMA is used for many-to-one communication in each D2D cluster. This paper proposes a joint channel allocation and power control algorithm which decomposes the resource allocation problem into two subproblems: channel allocation and power control. Matching theory is utilized to allocate channels for D2D clusters and sequential convex programming is applied to transform the optimization target to a convex problem before solving it via genetic algorithm. Simulation results indicate the superiority of our algorithm in improving the system throughput on the basis of meeting users’ needs for files.


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