Performance Evaluation of UAV-Based NOMA Networks with Hardware Impairment (original) (raw)
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UAV-Aided Multi-Way NOMA Networks With Residual Hardware Impairments
IEEE Wireless Communications Letters, 2020
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IEEE Access, 2021
We evaluate a downlink non-orthogonal multiple access (NOMA)-enable UAV-aided communication system to address the demand of spectrum usage of unmanned aerial vehicles (UAVs). In this paper, multiple NOMA users are served by an UAV to improve the effective spectrum usage. Over Nakagami-m fading model, the performance of the system was investigated based on the analysis of outage probabilities (OPs) of the NOMA users, the ergodic rate, and symbol error rate of the system under two scenarios, i.e., perfect successive interference cancellation (pSIC) and imperfect successive interference cancellation (ipSIC). Additionally, the effects of the system parameters such as the transmit power and altitude of the UAV, the coefficients of channel model on the system performance were studied. The results demonstrate that the performance of the NOMA-based system is better compared with that of the conventional orthogonal multiple access (OMA)-based system in terms of OP, throughput and ergodic rate. Considering outage probabilities at the users, the system in the ipSIC case achieves the same performance as the pSIC case at a low transmit power of the UAV. In addition, an increase in the height of the UAV decreases the ergodic capacity of each user. INDEX TERMS Unmanned aerial vehicle, NOMA, outage probability, ergodic capacity.
Enabling unmanned aerial vehicle to serve ground users in downlink NOMA system
Bulletin of Electrical Engineering and Informatics, 2022
The emergence of internet-of-things (IoT) devices in homes and industry, has resulted in the current and future generation of wireless communications facing unique challenges in spectral efficiency, energy efficiency, and massive connectivity issues. Non-orthogonal multiple access (NOMA) has been proposed as a viable solution to address these challenges as it offers low-latency, spectral efficiency, and massive connectivity capabilities, which are key requirements in upcoming next-generation networks. In addition, another technology that has emerged as a solution to spectral efficiency and coverage is an unmanned aerial vehicle (UAV). Therefore, the combination of UAVs with NOMA has great potential to minimize the challenges and maximize the benefits. Specifically, we investigate the outage performance of the NOMA-UAV network over Nakagami-m channel fading. To this end, we derive a closed-form outage performance metric. The formulated framework is validated using simulations to verify the effectiveness of the proposed solution.
Uavnoma: A UAV-NOMA Network Model under Non-Ideal Conditions
Journal of Open Research Software, 2022
Uavnoma is a set of Python functions and a front-end script for modeling, studying, and analyzing the communication system composed by an unmanned aerial vehicle (UAV) and two ground users. We assume that the UAV acts as an aerial base station to serve the users according to non-orthogonal multiple access (NOMA) principles. For more practical insights, residual hardware impairments (RHI) and imperfect successive interference cancellation (ipSIC) are considered. More specifically, uavnoma allows the modelers to study and visualize the system performance in terms of achievable rate and outage probability. Additionally, the package produces figures and tables showcasing results from the specified performance metrics.
UAV-assisted underlay CR-NOMA network: performance analysis
Bulletin of Electrical Engineering and Informatics, 2022
We highlight the potential of non-orthogonal multiple access (NOMA) integration with unmanned aerial vehicle (UAV) for future communications networks in beyond 5 gen-eration (B5G) networks to enhance cellular communication, support massive connec-tions and increase data rates. We consider a scenario, where a UAV communicates in a downlink underlay cognitive radio based NOMA network (CR-NOMA) with two destination users, a cellular device, and a primary destination following Nakagami-mfading distribution. We study the impact of perfect and imperfect successive interfer-ence cancellation (SIC) on outage probability (OP). To help analyze this impact, we derive exact outage results for different network users under perfect and imperfect SIC conditions. Consequently, we make use of Monte Carlo simulations to confirm the analytical results.
On the Performance of Non-Orthogonal Multiple Access (NOMA): Terrestrial vs. Aerial Networks
2020
Non-orthogonal multiple access (NOMA) is a promising multiple access technique for beyond fifth generation (B5G) cellular wireless networks, where several users can be served on a single time-frequency resource block, using the concepts of superposition coding at the transmitter and selfinterference cancellation (SIC) at the receiver. For terrestrial networks, the achievable performance gains of NOMA over traditional orthogonal multiple access (OMA) are well-known. However, the achievable performance of NOMA in aerial networks, compared to terrestrial networks, is not well-understood. In this paper, we provide a unified analytic framework to characterize the outage probabilities of users considering various network settings, such as i) uplink and downlink NOMA and OMA in aerial networks, and ii) uplink and downlink NOMA and OMA in terrestrial networks. In particular, we derive closed-form rate outage probability expressions for two users, considering line-of-sight (LOS) Rician fading channels. Numerical results validate the derived analytical expressions and demonstrate the difference of outage probabilities of users with OMA and NOMA transmissions. Numerical results unveil that the optimal UAV height increases with the increase in Rice-K factor, which implies strong line-of-sight (LOS) conditions. Index Terms-Non-orthogonal multiple access (NOMA), Unmanned aerial vehicle (UAV), terrestrial/aerial networks, SINR, outage probability.
Employing non-orthogonal multiple access scheme in UAV-based wireless networks
Bulletin of Electrical Engineering and Informatics, 2021
This paper studies the two-hop transmission relying unmanned aerial vehicle (UAV) relays which is suitable to implement in the internet of things (IoT) systems. To enhance system performance in order to overcome the large scale fading between the base station (BS) and destination as well as achieve the higher spectrum efficiency, where non-orthogonal multiple access (NOMA) strategies were typically applied for UAV relays to implement massive connections transmission. In particular, outage probability is evaluated via signal to noise ratio (SNR) criterion so that the terminal node can obtain reasonable performance. The derivations and analysis results showed that the considered fixed power allocation scheme provides performance gap among two signals at destination.The numerical simulation confirmed the exactness of derived expressions in the UAV assisted system.
A Unified Framework for HS-UAV NOMA Networks: Performance Analysis and Location Optimization
IEEE Access, 2020
In this paper, we propose a unified framework for hybrid satellite/unmanned aerial vehicle (HS-UAV) terrestrial non-orthogonal multiple access (NOMA) networks, where satellite aims to communicate with ground users with the aid of a decode-forward (DF) UAV relay by using NOMA protocol. All users are randomly deployed to follow a homogeneous Poisson point process (PPP), which is modeled by the stochastic geometry approach. To reap the benefits of satellite and UAV, the links of both satellite-to-UAV and UAV-to-ground user are assumed to experience Rician fading. More practically, we assume that perfect channel state information (CSI) is infeasible at the receiver, as well as the distance-determined path-loss. To characterize the performance of the proposed framework, we derive analytical approximate closed-form expressions of the outage probability (OP) for the far user and the near user under the condition of imperfect CSI. Also, the system throughput under delay-limited transmission mode is evaluated and discussed. In order to obtain more insights, the asymptotic behavior is explored in the high signal-to-noise ratio (SNR) region and the diversity orders are obtained and discussed. To further improve the system performance, based on the derived approximations, we optimize the location of the UAV to maximize the sum rate by minimizing the average distance between the UAV and users. The simulated numerical results show that: i) there are error floors for the far and the near users due to the channel estimation error; ii) the outage probability decreases as the Rician factor K increasing, and iii) the outage performance and system throughput performance can be further improved considerably by carefully selecting the location of the UAV. INDEX TERMS Non-orthogonal multiple access (NOMA), unmanned aerial vehicle (UAV), satellite communication, location optimization, Rician fading channels.
Performance of Hybrid Satellite-UAV NOMA Systems
This paper investigates the performance of non-orthogonal multiple access (NOMA) based hybrid satellite-unmanned aerial vehicle (UAV) systems, where a low Earth orbit (LEO) satellite communicates with the ground users via a decode and forward (DF) UAV relay. We investigate a two NOMA users system, where a far user (FU) and a near user (NU) are served by the UAV which is located at a certain height above the origin of the coverage circle. The channel between satellite and UAV is assumed to follow a Shadowed-Rician fading and the channels between UAV and users are assumed to follow a Nakagami-m fading. New closed-form expressions of the outage probabilities for the two users and the system are derived. Different from other work in literature, we take into consideration different parameters affecting the total link budget. Additionally, we propose an algorithm for minimizing the system outage probability. The mathematical analysis is verified by extensive representative Monte-Carlo (MC)...
Outage Analysis of Ground-Aerial NOMA With Distinct Instantaneous Channel Gain Ranking
IEEE Transactions on Vehicular Technology, 2019
Future wireless networks envision to provide seamless connectivity to a multitude of devices including unmanned aerial vehicles (UAVs). This paper investigates a unique case where we aim to serve ground users and a UAV, with distinct channel characteristics and access environments in threedimensional (3D) space, based on non-orthogonal multiple access (NOMA). Unlike traditional distance-based ranking or channelgain-based ranking, we apply NOMA in uplink and downlink transmissions by evaluating instantaneous channel gain and distance-dependant path-loss together. The communication links of ground and aerial users have different fading environments and path losses which make it crucial to analyse instantaneous channel gain before applying NOMA. To this end, we derive new mathematical expressions of outage probabilities in downlink and uplink transmissions based on instantaneous distinct signal power (IDSP) for each user, verified by simulations. Next, we investigate the impact of different system parameters, e.g. data rate, path loss exponent, channel fading characteristics and UAV height, on outage behaviour. The results confirm that groundaerial NOMA can be successfully employed in future wireless networks to provide cellular connectivity with improved spectral efficiency to a broader range of devices with individual data rate requirements. Index Terms-Non-orthogonal multiple access (NOMA), user pairing, Unmanned aerial vehicles (UAV). I. INTRODUCTION T HE STORM of wireless devices is on the rise with nearly twenty-billion devices to be deployed by 2020 [1]. Unmanned aerial vehicles (UAVs), commonly referred to as drones, have become popular in the recent years with a variety of usuage in a range of applications including live audio/video streaming, package delivery, road traffic monitoring, network provision in catastrophic scenarios, farm monitoring and other agriculture applications, etc. Rapid advancements in drone technology are deriving research interests towards UAVs as aerial base stations (BSs) to deliver on demand and reliable service to desired users, or as relays [2] to help regular terrestrial networks in extending the network coverage, or as cellular-connected UAVs for data delivery or surveillance, etc. In beyond 5G (B5G) cellular networks, fully autonomous or remotely operated UAVs stand as a potential candidate of acquiring communication link with BS [3], [4]. While the drones are present in the air, they need to be served