scholarly journals Power Control Method for Energy Efficient Buffer-Aided Relay Systems

Energies ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 3234
Author(s):  
Jingon Joung ◽  
Han Lim Lee ◽  
Jian Zhao ◽  
Xin Kang
Keyword(s):  
Energy Efficiency ◽  
Power Control ◽  
Control Method ◽  
Relay Node ◽  
Destination Node ◽  
Transmit Power ◽  
Channel Condition ◽  
Relay Systems ◽  
Fixed Power ◽  
Fitting Model

In this paper, a power control method is proposed for a buffer-aided relay node (RN) to enhance the energy efficiency of the RN system. By virtue of a buffer, the RN can reserve the data at the buffer when the the channel gain between an RN and a destination node (DN) is weaker than that between SN and RN. The RN then opportunistically forward the reserved data in the buffer according to channel condition between the RN and the DN. By exploiting the buffer, RN reduces transmit power when it reduces the transmit data rate and reserve the data in the buffer. Therefore, without any total throughput reduction, the power consumption of RN can be reduced, resulting in the energy efficiency (EE) improvement of the RN system. Furthermore, for the power control, we devise a simple power control method based on a two-dimensional surface fitting model of an optimal transmit power of RN. The proposed RN power control method is readily and locally implementable at the RN, and it can significantly improve EE of the RN compared to the fixed power control method and the spectral efficiency based method as verified by the rigorous numerical results.

An Efficient Distributed Single-hop Relay Supporting (EDSRS) MAC Protocol for Wireless Sensor Networks

2019 ◽  
Vol 9 (2) ◽  
pp. 153-164
Author(s):  
Arvind Kakria ◽  
Trilok Chand Aseri
Keyword(s):  
Energy Efficiency ◽  
Cooperative Communication ◽  
Mimo Systems ◽  
Mac Protocol ◽  
Multiple Input Multiple Output ◽  
Relay Node ◽  
Base Stations ◽  
Destination Node ◽  
Distributed Coordination ◽  
Hardware Complexity

Background & Objective: Wireless communication has immensely grown during the past few decades due to significant demand for mobile access. Although cost-effective as compared to their wired counterpart, maintaining good quality-of-service (QoS) in these networks has always remained a challenge. Multiple-input Multiple-output (MIMO) systems, which consists of multiple transmitter and receiver antennas, have been widely acknowledged for their QoS and transmit diversity. Though suited for cellular base stations, MIMO systems are not suited for small-sized wireless nodes due to their hardware complexity, cost, and increased power requirements. Cooperative communication that allows relays, i.e. mobile or fixed nodes in a communication network, to share their resources and forward other node’s data to the destination node has substituted the MIMO systems nowadays. To harness the full benefit of cooperative communication, appropriate relay node selection is very important. This paper presents an efficient single-hop distributed relay supporting medium access control (MAC) protocol (EDSRS) that works in the single-hop environment and improves the energy efficiency and the life of relay nodes without compensating the throughput of the network. Methods: The protocol has been simulated using NS2 simulator. The proposed protocol is compared with energy efficient cooperative MAC protocol (EECOMAC) and legacy distributed coordination function (DCF) on the basis of throughput, energy efficiency, transmission delay and an end to end delay with various payload sizes. Result and Conclusion: The result of the comparison indicates that the proposed protocol (EDSRS) outperforms the other two protocols.

scholarly journals Improving Energy Efficiency Fairness of Wireless Networks: A Deep Learning Approach

Energies ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 4300 ◽  
Author(s):  
Hoon Lee ◽  
Han Seung Jang ◽  
Bang Chul Jung
Keyword(s):  
Energy Efficiency ◽  
Wireless Networks ◽  
Deep Learning ◽  
Power Control ◽  
Control Method ◽  
Optimal Solution ◽  
Control Policy ◽  
Maximization Problem ◽  
Optimization Approach ◽  
Conventional Optimization

Achieving energy efficiency (EE) fairness among heterogeneous mobile devices will become a crucial issue in future wireless networks. This paper investigates a deep learning (DL) approach for improving EE fairness performance in interference channels (IFCs) where multiple transmitters simultaneously convey data to their corresponding receivers. To improve the EE fairness, we aim to maximize the minimum EE among multiple transmitter–receiver pairs by optimizing the transmit power levels. Due to fractional and max-min formulation, the problem is shown to be non-convex, and, thus, it is difficult to identify the optimal power control policy. Although the EE fairness maximization problem has been recently addressed by the successive convex approximation framework, it requires intensive computations for iterative optimizations and suffers from the sub-optimality incurred by the non-convexity. To tackle these issues, we propose a deep neural network (DNN) where the procedure of optimal solution calculation, which is unknown in general, is accurately approximated by well-designed DNNs. The target of the DNN is to yield an efficient power control solution for the EE fairness maximization problem by accepting the channel state information as an input feature. An unsupervised training algorithm is presented where the DNN learns an effective mapping from the channel to the EE maximizing power control strategy by itself. Numerical results demonstrate that the proposed DNN-based power control method performs better than a conventional optimization approach with much-reduced execution time. This work opens a new possibility of using DL as an alternative optimization tool for the EE maximizing design of the next-generation wireless networks.

scholarly journals Uplink Transmit Power Control for Single-Carrier Grouped FDMA with Iterative Multiuser Detection

2019 ◽  
Vol 10 (1) ◽  
pp. 119
Author(s):  
Yong-Sang Cho ◽  
Yun-Seong Kang ◽  
Moonsik Min
Keyword(s):  
Power Control ◽  
Multiuser Detection ◽  
Spectral Efficiency ◽  
Control Method ◽  
Signal To Noise Ratio ◽  
Transmit Power ◽  
Time Frequency ◽  
Evolution Simulation ◽  
Single Carrier ◽  
Iterative Multiuser Detection

We consider an uplink power allocation scheme for single-carrier frequency-division multiple access (FDMA) with iterative multiuser detection, called single-carrier grouped FDMA (SC-GFDMA). SC-GFDMA is a non-orthogonal scheme in which several users share a single time-frequency resource. Hence, the uplink signal of a user can be regarded as both a signal and a source of interference. The signal power of each user should be sufficiently high to ensure reliable signal detection and sufficiently low to suppress inter-user interference. That is, the transmit power of each user should be adjusted appropriately to achieve high spectral efficiency. In this context, a power control method for an uplink SC-GFDMA system is proposed by analyzing the signal-to-interference-plus-noise ratios of users sharing each time-frequency resource. In particular, the uplink spectral efficiency is improved by limiting the transmit power of each user according to a criterion derived using a semi-analytic method called signal-to-noise ratio-variance density evolution. Simulation results demonstrate that the proposed method can significantly increase the spectral efficiency of the system, even with a considerably reduced total transmit power.

scholarly journals Wireless Energy Harvesting in Internet-of-Things Communication Systems with Optimized Energy Efficiency using PSO

2019 ◽  
Vol 8 (9S) ◽  
pp. 402-410
Keyword(s):  
Energy Efficiency ◽  
Communication Systems ◽  
Relay Node ◽  
Destination Node ◽  
Wireless Energy Transfer ◽  
Swarm Optimization ◽  
Iot Applications ◽  
Wide Range ◽  
Analysis System ◽  
Wireless Energy Harvesting

IoT is an emerging technology having a wide range of application areas. IoT applications are also affecting human lives. But these small devices are battery powered which is major problem for IoT systems. Wireless energy transfer is a good solution for such systems. Both information and energy can be transmitted together by wireless energy. In this paper, time splitting-based relaying (TSR) protocol is used by relay node to harvest the energy in IoT system. Here, dual-hop IoT system is considered for analysis. System with three different Wi-Fi protocols is examined against the energy efficiency at the destination node. All three protocols are analysed individually. Further, Particle Swarm Optimization (PSO) technique is used to optimize the energy efficiency of the considered IoT system.

scholarly journals Greedy Based Radio Resource Allocation Algorithm with Water Filling Power Control Scheme in D2D Underlaying Communication

2021 ◽  
Author(s):  
Rezha Aulia Riyanda ◽  
Nachwan Mufti Adriansyah ◽  
Vinsensius Sigit Widhi Prabowo
Keyword(s):  
Resource Allocation ◽  
Energy Efficiency ◽  
Power Control ◽  
Greedy Algorithm ◽  
Spectral Efficiency ◽  
Channel Condition ◽  
Resource Allocation Algorithm ◽  
Allocation Algorithm ◽  
Control Scheme ◽  
Water Filling

Device to Device (D2D) is communication between two devices directly without the intervention of eNodeB.This communication can improve sum-rate, spectral efficiency, and decrease the workload of eNodeBbecause using the same spectrum frequency with Cellular User Equipment (CUE). But this communicationshould use the same resource simultaneously with CUE which is called D2D underlaying. This sharingresources also causes interference and should be managed using the resource allocation algorithm. In thiswork, the resource allocation is allocated in a single cell and uplink communication using joint greedyalgorithm with water filling power control scheme. This algorithm is compared with greedy, joint greedy,and greedy algorithm with water filling power control scheme. Joint greedy algorithm works based on thecapacity of eNodeB and D2D pair. While in water filling power control, the power of the user is managedbased on the channel condition and impact to energy efficiency. After all the resource is allocated, theparameter performance of the system is calculated, such as spectral efficiency, energy efficiency, and D2Dfairness. From the simulation result, joint greedy algorithm with water filling power control scheme result29,34 bps/Hz in spectral efficiency, 0.939 x 107 bps/watt in energy efficiency, and 0,996 in D2D fairness.

scholarly journals Energy Efficiency of Uplink Cell-Free Massive MIMO With Transmit Power Control in Measured Propagation Channel

2021 ◽  
Vol 2 ◽  
pp. 792-804
Author(s):  
Thomas Choi ◽  
Masaaki Ito ◽  
Issei Kanno ◽  
Jorge Gomez-Ponce ◽  
Colton Bullard ◽  
...  
Keyword(s):  
Energy Efficiency ◽  
Power Control ◽  
Massive Mimo ◽  
Propagation Channel ◽  
Transmit Power ◽  
Transmit Power Control

scholarly journals Relay Selection for Capacity Increase in Underwater Acoustic Sensor Network

Sensors ◽  
2021 ◽  
Vol 21 (19) ◽  
pp. 6605
Author(s):  
Ramsha Narmeen ◽  
Jaehak Chung
Keyword(s):  
Energy Efficiency ◽  
Relay Node ◽  
Propagation Delay ◽  
Sensor Nodes ◽  
Destination Node ◽  
Delivery Ratio ◽  
Medium Access ◽  
Long Distance ◽  
Underwater Acoustic ◽  
Data Packets

In long distance sensor nodes, propagation delay is the most crucial factor for the successful transmission of data packets in underwater acoustic sensors networks (UWAs). Therefore, to cope with the problem of propagation delay, we propose examining and selecting the best relay node (EBRN) technique based on checking the eligibility and compatibility of RN and selecting the best RN for UWAs. In the EBRN technique, the source node (S) creates a list of the best RNs, based on the minimum propagation delay to the midpoint of a direct link between S and the destination node (D). After that, the S attaches the list of selected RNs and transmit to the D along with data packets. Finally, from the list of selected RNs, the process of retransmission is performed. To avoid collision among control packets, we use a backoff timer that is calculated from the received signal strength indicator (RSSI), propagation delay and transmission time, whereas the collision among data packets is avoided by involving single RN in a particular time. The performance of the proposed EBRN technique is analyzed and evaluated based on throughput, packet loss rate (LR), packet delivery ratio (PDR), energy efficiency, and latency. The simulation results validate the effectiveness of the proposed EBRN technique. Compared with the existing schemes such as underwater cooperative medium access control (UCMAC) and shortest path first (SPF), the proposed EBRN technique performs remarkably well by increasing the throughput, PDR, and energy efficiency while decreasing the latency and LR in UWAs.

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