scholarly journals Joint Scheduling and Power Allocation Using Non-Orthogonal Multiple Access in Multi-Cell Beamforming Networks

Electronics ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 896
Author(s):  
Kyungseop Shin ◽  
Ohyun Jo
Keyword(s):  
Power Allocation ◽  
Multiple Access ◽  
Performance Evaluations ◽  
System Level ◽  
Smart Devices ◽  
Dense Networks ◽  
Throughput Gain ◽  
Access Scheme ◽  
Network Technologies ◽  
Efficient Power

The proliferation of smart devices has boosted the improvement of wireless network technologies. Herein, networking functions should be properly guaranteed even in highly dense environments in terms of service quality and data rate. In this paper, we present an efficient power allocation algorithm using non-orthogonal multiple access and smart array antennas to increase the capacity in highly overlapped multi-cell environments. We evaluate the proposed algorithm and compare with the conventional orthogonal multiple access scheme with smart antennas. Through intensive simulations and experiments at the system level for performance evaluations, it is confirmed that the proposed scheme obtains a drastic throughput gain up to 50% in the overlapped region of highly dense networks.

Subcarrier and Power Allocation Algorithm for Spectral Efficiency Maximization in Superposition Coding OFDMA Systems

2015 ◽  
Vol 24 (05) ◽  
pp. 1550061
Author(s):  
Mateus de Paula Marques ◽  
Taufik Abrão
Keyword(s):  
Power Allocation ◽  
Spectral Efficiency ◽  
Time Complexity ◽  
Multiple Access ◽  
Optimization Problem ◽  
Frequency Division ◽  
Superposition Coding ◽  
Ofdma System ◽  
Transmission Strategy ◽  
Throughput Gain

This paper addresses the optimization problem on subcarrier and power allocation of orthogonal frequency division multiple access (OFDMA) system under spectral efficiency (SE) metric when deploying superposition coding (SC) transmission strategy. An algorithm with polynomial time complexity, of the order of (UN log 2(N)) has been proposed for sub-optimal SE maximization. Results indicate that the system SE increases with the use of SC technique. Besides, the throughput gain with SC adoption increases when the number of users (U) approaches the number of subcarriers (N) available in the system.

Energy-Efficient Power Allocation for Millimeter-Wave System With Non-Orthogonal Multiple Access and Beamforming

2019 ◽  
Vol 68 (8) ◽  
pp. 7877-7889 ◽  
Author(s):  
Xiangbin Yu ◽  
Xiaoyu Dang ◽  
Benben Wen ◽  
Shu-Hung Leung ◽  
Fangcheng Xu
Keyword(s):  
Power Allocation ◽  
Millimeter Wave ◽  
Energy Efficient ◽  
Multiple Access ◽  
Wave System ◽  
Efficient Power

Sum rate capacity of non-orthogonal multiple access scheme with optimal power allocation

2021 ◽  
pp. 154851292098353
Author(s):  
Lokesh Bhardwaj ◽  
Ritesh Kumar Mishra ◽  
Ravi Shankar
Keyword(s):  
Power Allocation ◽  
Multiple Access ◽  
Signal To Noise Ratio ◽  
Optimal Power Allocation ◽  
Cumulative Density Function ◽  
Optimal Power ◽  
Power Domain ◽  
Access Scheme ◽  
Rate Capacity ◽  
Sum Rate

In this work, the performance of the downlink non-orthogonal multiple access (NOMA) technique is investigated for two users considering optimal power allocation factors. The power domain NOMA differentiates the users based on channel gains by providing different power levels and it is demonstrated that optimal power allocation is only possible when the gain ratio is maximum. Further, the range of optimal power levels is derived for the strong user having better channel conditions. Furthermore, the outage probability (OP) has been derived for ordered NOMA in the downlink through the cumulative density function-based approach. The simulation results demonstrate the improvement in sum rate capacity for optimal power allocation as compared to random power allocation, and the OP reduces with the signal-to-noise ratio more sharply for the stronger user.

scholarly journals An Efficient Resource Allocation for Massive MTC in NOMA-OFDMA Based Cellular Networks

Electronics ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 705
Author(s):  
Yali Wu ◽  
Shuang Zhang ◽  
Zhengxuan Liu ◽  
Xiaoshuang Liu ◽  
Jianfeng Li
Keyword(s):  
Resource Allocation ◽  
Energy Efficiency ◽  
Power Allocation ◽  
Multiple Access ◽  
Random Access ◽  
Iterative Algorithms ◽  
Low Complexity ◽  
Access Scheme ◽  
Efficient Resource ◽  
Resource Allocation Scheme

To alleviate random access congestion and support massive-connections with less energy consumption for machine-type communications (MTC) in the 5G cellular network, we propose an efficient resource allocation for massive MTC (mMTC) with hybrid non-orthogonal multiple access (NOMA)-orthogonal frequency division multiple access (OFDMA). First, a hybrid multiple access scheme, including the NOMA-based congestion-alleviating access scheme (NCAS) and OFDMA-based congestion-alleviating access scheme (OCAS), is proposed, in which the NOMA based devices coexist with OFDMA based ones. Then, aiming at maximizing the system access capacity, a traffic-aware resource blocks (RBs) allocation is investigated to optimize RBs allocation for preamble transmission and data packets transmission, as well as to optimize the RBs allocation between NCAS and OCAS for the RBs usage efficiency improvement. Next, aiming at the problem of high computational complexity and improving energy efficiency in hybrid NOMA-OFDMA based cellular M2M communications, this paper proposes an improved low complexity power allocation algorithm. The feasibility conditions of power allocation solution under the maximum transmit power constraints and quality of service (QoS) requirements of the devices is investigated. The original non-convex optimization problem is solved under the feasibility conditions by two iterative algorithms. Finally, a device clustering scheme is proposed based on the channel gain difference and feasible condition of power allocation solution, by which NOMA based devices and OFDMA based devices can be determined. Simulation results show that compared with non-orthogonal random access and transmission (NORA-DT), the proposed resource allocation scheme for hybrid NOMA-OFDMA systems can efficiently improve the performance of access capacity and energy efficiency.

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