Subcarrier-User Assignment in Downlink NOMA for Improving Spectral Efficiency and Fairness

Abd‐Elnaby, Mohammed; Sedhom, Germien G.; Elwekeil, Mohamed

doi:10.1109/access.2020.3047985

Cited by 18 publications

(14 citation statements)

References 26 publications

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“…An SUA algorithm for the NOMA system is introduced in [23] to develop SE by raising the total system sum-rate and preserving large channel gain distinction between the joined users per subcarrier to improve the SIC implementation. Two SUA algorithms for the NOMA system, namely "worst subcarrier first based subcarrier-user assignment algorithm" (WSF-SUAA) and "spectral efficiency maximization-based subcarrier-user assignment algorithm" (SEM-SUAA) are implemented in [24]. These algorithms aim to improve SE, enhance the data rate of weak users, improve the fairness between users, and reduce the outage probability.…”

Section: Related Workmentioning

confidence: 99%

“…Furthermore, each user can get data from various subcarriers. To decrease the excessive multiple-access, we assume that each user can employ only one subcarrier, and each subcarrier can be allotted to 𝑁 users, where 𝑁 is the number of paired users on the subcarrier s. Accordingly, the whole number of users is 𝐾 = 𝑁 𝑆 [18], [23], [24], and [42]. Also, the BS divides its total transmit power 𝑃 𝑇 among subcarriers such that…”

Section: A System Modelmentioning

confidence: 99%

“…Specifically, we present a new PA algorithm to enhance the total weighted energy efficiency (WEE) and guarantee fairness between users. Concerning the UP problem, we involve previous existing algorithms which are the conventional user pairing (CUP) algorithm [12] and the worst subcarrier first (WSF) algorithm [24] with the proposed PA algorithm.…”

Section: Introductionmentioning

confidence: 99%

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An Optimum Weighted Energy Efficiency Approach for Low Complexity Power Allocation in Downlink NOMA

Abd‐Elnaby

Sedhom²,

El-Rabaie

et al. 2022

IEEE Access

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Non-orthogonal multiple access (NOMA) has emerged as a significant technique for 5G wireless networks because it increases device connectivity, spectral efficiency, and energy efficiency. The advantages of the NOMA system rely on the employed resource allocation schemes, which include power allocation (PA) and subcarrier user assignment (SUA). Therefore, this paper concentrates on suggesting a PA approach called a weighted energy efficiency power allocation (WEE-PA) approach to maximize the total weighted energy efficiency (WEE) in the NOMA system. Also, the proposed WEE-PA approach boosts the fairness between users, the minimum user rate in the system, the outage probability, and the average data rate per weak user. Therefore, the PA optimization problem defines as an optimization problem with a total power constraint and a set of dynamic PA parameters to maximize the WEE and ensure user fairness. The original optimization problem separates into two sub-problems, and an iterative approach is employed to solve these two sub-problems alternatingly and reduce the computational complexity. Since the optimization problem is non-convex, the sequential quadratic programming (SQP) technique is applied to resolve it and find the corresponding optimal solution. Our simulations confirm that using our proposed WEE-PA algorithm to allocate mutual resources furnishes better results than existing PA schemes.INDEX TERMS Non-orthogonal multiple access (NOMA), power allocation (PA), subcarrier user assignment (SUA), weighted energy efficiency (WEE).

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Section: Related Workmentioning

confidence: 99%

Section: A System Modelmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

An Optimum Weighted Energy Efficiency Approach for Low Complexity Power Allocation in Downlink NOMA

Abd‐Elnaby

Sedhom²,

El-Rabaie

et al. 2022

IEEE Access

Self Cite

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“…It is demonstrated that the capacity of Fair-NOMA with K users can always be enhanced for each additional user to the network. For the downlink NOMA system, two subcarrier-user assignment algorithms (SUAAs) are presented in [14] to improve spectral efficiency, outage probability, fairness, and weak users' data rate. Two types of SUAA are proposed SUAA.…”

Section: Related Workmentioning

confidence: 99%

Efficient User Pairing for Performance Enhancement of Downlink NOMA Systems

Alraddady¹

2022

Computer Systems Science and Engineering

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In this paper, the resource allocation problem for user pairing (UP) in downlink non-orthogonal multiple access (NOMA) systems is investigated. NOMA allows the use of one subcarrier for more than one user at the same time, thus increases the total capacity of the wireless communication system. However, users pairing is a challenging task in the NOMA systems, because a good channel quality subcarrier should be selected and allocated for the user to enhance the performance of NOMA systems. The proposed UP algorithm aims to enhance the sum rate of the paired users per subcarrier and consequently enhance the total sum rate of downlink NOMA systems. Moreover, the proposed UP algorithm target to improve the fairness of the users. The proposed UP algorithm is based on a simple search for the subcarrier with the minimum average channel gains to be assigned its paired users and then excluding it from the next searching process. The proposed scheme ensures the higher channel gain for users by giving the priority to the subcarrier with the minimum average channel gains during the user pairing process. The simulation results demonstrate that the proposed UP algorithm can not only enhance the total sum rate compared with the random UP and conventional UP but also can enhance the fairness of the users. Moreover, it is clearly seen that the proposed UP algorithm provides the lowest outage probability.

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“…In addition, a power allocation scheme is also proposed to guarantee the users' performance. In the case of multiple NOMA users, the study in [21] aims to improve the spectral efficiency, data rate, fairness, and outage probability of multiple NOMA users by proposing two sub-carrier user assignment algorithms (SUAAs). The pairing procedure of both algorithms is predominantly determined by increasing the channel conditions of the designated paired users per subcarrier to enhance the data rate of each individual user.…”

Section: A Related Workmentioning

confidence: 99%

UAV-Enabled Cooperative NOMA with Indoor- Outdoor User-Paring and SWIPT in kappa-mu Channels

Al-Dweik¹,

Alqahtani²,

Alsusa³

2021

Preprint

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<div>This work presents a performance analysis on cooperative non-orthogonal multiple accesses (C-NOMA) when assisted with energy harvesting enabled unmanned aerial vehicle (UAV) decode-and-forward (DF) relaying. In particular, two scenarios are considered, an outdoor-indoor one, where the NOMA signal propagates through outdoor-to-indoor, and a conventional outdoor scenario where the channel gains follow a k-u generalized fading model. The objectives of this work is to analyze the downlink performance of this C-NOMA system and derive closed-form expressions for the outage probability (OP), ergodic capacity (EC), throughput and energy efficiency (EE) for the users assuming imperfect successive interference cancellation (SIC). In particular, the OP approach considers the individual users’ rate where it is required to satisfy certain quality of service (QoS) requirements. The results provide insights into the considered performance metrics relative to key parameters such as power allocation, power splitting factor, fading parameters, and residual interference. Extensive simulations results are presented to validate the accuracy of the derived expressions.</div>

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Subcarrier-User Assignment in Downlink NOMA for Improving Spectral Efficiency and Fairness

Cited by 18 publications

References 26 publications

An Optimum Weighted Energy Efficiency Approach for Low Complexity Power Allocation in Downlink NOMA

An Optimum Weighted Energy Efficiency Approach for Low Complexity Power Allocation in Downlink NOMA

Efficient User Pairing for Performance Enhancement of Downlink NOMA Systems

UAV-Enabled Cooperative NOMA with Indoor- Outdoor User-Paring and SWIPT in kappa-mu Channels

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