scholarly journals Optimisation of FeICIC for energy efficiency and spectrum efficiency in LTE‐advanced HetNets

2016 ◽  
Vol 52 (11) ◽  
pp. 982-984 ◽  
Author(s):  
A. Merwaday ◽  
I. Güvenç
Keyword(s):  
Energy Efficiency ◽  
Spectrum Efficiency ◽  
Lte Advanced

scholarly journals User Clustering and Power Allocation for Energy Efficiency Maximization in Downlink Non-Orthogonal Multiple Access Systems

2021 ◽  
Vol 11 (2) ◽  
pp. 716
Author(s):  
Ruibiao Chen ◽  
Fangxing Shu ◽  
Kai Lei ◽  
Jianping Wang ◽  
Liangjie Zhang
Keyword(s):  
Energy Efficiency ◽  
Power Allocation ◽  
Multiple Access ◽  
Spectrum Efficiency ◽  
Lagrangian Multiplier ◽  
Efficiency Gain ◽  
Optimal Power Allocation ◽  
Optimal Power ◽  
User Clustering ◽  
Cluster Dynamic

Non-orthogonal multiple access (NOMA) has been considered a promising technique for the fifth generation (5G) mobile communication networks because of its high spectrum efficiency. In NOMA, by using successive interference cancellation (SIC) techniques at the receivers, multiple users with different channel gain can be multiplexed together in the same subchannel for concurrent transmission in the same spectrum. The simultaneously multiple transmission achieves high system throughput in NOMA. However, it also leads to more energy consumption, limiting its application in many energy-constrained scenarios. As a result, the enhancement of energy efficiency becomes a critical issue in NOMA systems. This paper focuses on efficient user clustering strategy and power allocation design of downlink NOMA systems. The energy efficiency maximization of downlink NOMA systems is formulated as an NP-hard optimization problem under maximum transmission power, minimum data transmission rate requirement, and SIC requirement. For the approximate solution with much lower complexity, we first exploit a quick suboptimal clustering method to assign each user to a subchannel. Given the user clustering result, the optimal power allocation problem is solved in two steps. By employing the Lagrangian multiplier method with Karush–Kuhn–Tucker optimality conditions, the optimal power allocation is calculated for each subchannel. In addition, then, an inter-cluster dynamic programming model is further developed to achieve the overall maximum energy efficiency. The theoretical analysis and simulations show that the proposed schemes achieve a significant energy efficiency gain compared with existing methods.

scholarly journals Joint UAV channel modeling and power control for 5G IoT networks

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Xiuhua Fu ◽  
Tian Ding ◽  
Rongqun Peng ◽  
Cong Liu ◽  
Mohamed Cheriet
Keyword(s):  
Energy Efficiency ◽  
Power Control ◽  
Channel Model ◽  
Path Loss ◽  
Channel Modeling ◽  
Signal Propagation ◽  
Spectrum Efficiency ◽  
Propagation Path ◽  
Control Factor ◽  
The Impact

AbstractThis paper studies the communication problem between UAVs and cellular base stations in a 5G IoT scenario where multiple UAVs work together. We are dedicated to the uplink channel modeling and the performance analysis of the uplink transmission. In the channel model, we consider the impact of 3D distance and multi-UAVs reflection on wireless signal propagation. The 3D distance is used to calculate the path loss, which can better reflect the actual path loss. The power control factor is used to adjust the UAV's uplink transmit power to compensate for different propagation path losses, so as to achieve precise power control. This paper proposes a binary exponential power control algorithm suitable for 5G networked UAV transmitters and presents the entire power control process including the open-loop phase and the closed-loop phase. The effects of power control factors on coverage probability, spectrum efficiency and energy efficiency under different 3D distances are simulated and analyzed. The results show that the optimal power control factor can be found from the point of view of energy efficiency.

Energy Efficiency of Heterogeneous Networks in LTE-Advanced

2011 ◽  
Vol 69 (1) ◽  
pp. 105-113 ◽  
Author(s):  
Chadi Khirallah ◽  
John S. Thompson
Keyword(s):  
Energy Efficiency ◽  
Heterogeneous Networks ◽  
Lte Advanced

scholarly journals Energy Efficiency Optimization in Cooperative Spectrum Sensing by NOMA

2018 ◽  
Vol 7 (3.12) ◽  
pp. 1125 ◽  
Author(s):  
Meenakshi Awasthi ◽  
J.Madhav Nigam ◽  
Vijay Kumar
Keyword(s):  
Energy Efficiency ◽  
Cognitive Radio ◽  
Cooperative Spectrum Sensing ◽  
Basic Feature ◽  
Spectrum Efficiency ◽  
Superior Performance ◽  
Secondary Users ◽  
Energy Efficiency Improvement ◽  
5G Systems ◽  
Multiple Primary Users

Energy efficiency improvement is a major point of concern in cooperative scenario of cognitive radio networks, so as to compensate the overhead occurred due to power consumed by multiple numbers of secondary users. Non-orthogonal multiple access (NOMA) is a potential technique to get the higher spectrum efficiency for 5G systems. The basic feature of NOMA is to utilize the same channel, time and code but at different power levels, which results in higher spectrum efficiency (SE). In this article, firstly the cognitive radio (CR) inspired NOMA is generalized by multiple primary users. Then, energy efficiency (EE) is optimized for the proposed system. An efficient algorithm is proposed for the non-convex fractional programming problem. Simulation results show the superior performance over conventional multiple accesstechniques.  

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