scholarly journals Outage Performance Analysis of Cell-Center/Edge Users Under Two Policies of Energy Harvesting

2019 ◽  
Vol 25 (4) ◽  
pp. 75-80
Author(s):  
Dinh-Thuan Do ◽  
Anh-Tu Le ◽  
Chi-Bao Le ◽  
Si-Phu Le ◽  
Hong-Nhu Nguyen ◽  
...  
Keyword(s):  
Energy Harvesting ◽  
Power Allocation ◽  
Base Station ◽  
Wireless Power ◽  
Factors Affecting ◽  
Outage Performance ◽  
Numerical Result ◽  
Center Edge ◽  
Energy Signal ◽  
Better Than

In this paper, two energy harvesting policies deploying in cooperative non-orthogonal multiple access (NOMA) systems are considered. After period of wireless power transfer, the NOMA users including cell-edge and cell-center users simultaneously transmit the superposition coded symbols to the base station (BS). In the last time slot, the BS decodes to achieve its signal based on superposition coded symbol with corresponding power allocation factors. This paper provides exact expressions of outage probability in two schemes. Performance gap of two NOMA users can be raised by providing different power allocation factors. It is confirmed by numerical result. Distance and data rate are main factors affecting outage performance. Scheme I exhibit scenario where power beacon transmits energy signal to NOMA user while the BS feeds energy to NOMA user in Scheme II. It is shown that outage performance of Scheme I is better than that of Scheme II.

scholarly journals SWIPT in mMIMO system with non-linear energy-harvesting terminals: protocol design and performance optimization

2019 ◽  
Vol 2019 (1) ◽  
Author(s):  
Kui Xu ◽  
Ming Zhang ◽  
Jie Liu ◽  
Nan Sha ◽  
Wei Xie ◽  
...  
Keyword(s):  
Energy Harvesting ◽  
Performance Optimization ◽  
Power Transmission ◽  
Base Station ◽  
Second Phase ◽  
Wireless Power ◽  
Half Duplex ◽  
Non Linear ◽  
Two Phases ◽  
And Performance

Abstract In this paper, we design the simultaneous wireless information and power transfer (SWIPT) protocol for massive multi-input multi-output (mMIMO) system with non-linear energy-harvesting (EH) terminals. In this system, the base station (BS) serves a set of uplink fixed half-duplex (HD) terminals with non-linear energy harvester. Considering the non-linearity of practical energy-harvesting circuits, we adopt the realistic non-linear EH model rather than the idealistic linear EH model. The proposed SWIPT protocol can be divided into two phases. The first phase is designed for terminals EH and downlink training. A beam domain energy beamforming method is employed for the wireless power transmission. In the second phase, the BS forms the two-layer receive beamformers for the reception of signals transmitted by terminals. In order to improve the spectral efficiency (SE) of the system, the BS transmit power- and time-switching ratios are optimized. Simulation results show the superiority of the proposed beam-domain SWIPT protocol on SE performance compared with the conventional mMIMO SWIPT protocols.

scholarly journals Energy consumption index minimized resource allocation in hybrid energy multiuser OFDM system with distributed antennas

2018 ◽  
Vol 17 ◽  
pp. 03015
Author(s):  
Huanhuan MAO ◽  
Pengcheng Zhu ◽  
Jiamin Li
Keyword(s):  
Resource Allocation ◽  
Energy Consumption ◽  
Energy Harvesting ◽  
Power Allocation ◽  
Base Station ◽  
Mixed Integer ◽  
Subcarrier Allocation ◽  
Ofdm System ◽  
Consumption Index ◽  
Distributed Antennas

Energy harvesting is one of the promising option for realization of green communication and has been a growing concern recently. In this paper, we address the downlink resource allocation in OFDM system with distributed antennas with hybrid power supply base station, where energy harvesting and non-renewable power sources are used complementarily. A joint subcarrier and power allocation problem is formulated for minimizing the net Energy Consumption Index (ECI) with system Quality of Service (QoS) and bit error rates constraint. The problem is a 0-1 mixed integer nonlinear programming problem due to the binary subcarrier allocation variable. To solve the problem, we design an algorithm based on Lagrange relaxation method and fraction programming which optimizes the power allocation and subcarrier allocation iteratively in two nests. Simulation results show that the proposed algorithm converges in a small number of iterations and can improve net ECI of system greatly.

scholarly journals Benefiting wireless power transfer scheme in power domain based multiple access: ergodic rate performance evaluation

2021 ◽  
Vol 10 (2) ◽  
pp. 785-792
Author(s):  
Anh-Tu Le ◽  
Minh-Sang Van Nguyen ◽  
Dinh-Thuan Do
Keyword(s):  
Power Allocation ◽  
Multiple Access ◽  
Wireless Power Transfer ◽  
Ergodic Capacity ◽  
Base Station ◽  
Power Transfer ◽  
Wireless Power ◽  
Transfer Scheme ◽  
Power Domain ◽  
Fixed Power

Power domain based multiple access scheme is introduced in this paper, namely Non-orthogonal multiple-access (NOMA). We deploy a wireless network using NOMA together with a wireless power transfer (WPT) scheme for dedicated user over Nakagami-$m$ fading channel. When combined, these promising techniques (NOMA and WPT) improve the system performance in term of ergodic performance at reasonable coefficient of harvested power. However, fixed power allocation factors for each NOMA user can be adjusted at the base station and it further provide performance improvement. We design a new signal frame to deploy a NOMA scheme in WPT which adopts a linear energy harvesting model. The ergodic capacity in such a NOMA network and power allocation factors can be updated frequently in order to achieve a fair distribution among NOMA users. The exact expressions of ergodic capacity for each user is derived. The simulation results show that an agreement between analytic performance and Monte-Carlo simulation can be achieved. 

scholarly journals Exploiting outage performance in device-to-device for user grouping

2021 ◽  
Vol 24 (2) ◽  
pp. 904
Author(s):  
Dinh-Thuan Do ◽  
Chi-Bao Le
Keyword(s):  
System Performance ◽  
Multiple Access ◽  
Base Station ◽  
Spectrum Efficiency ◽  
Frame Structure ◽  
Outage Performance ◽  
User Grouping ◽  
Numerical Result ◽  
Device To Device ◽  
New Form

The spectrum efficiency and massive connections are joint designed in new form of device-to-device for user grouping. A pair of users is implemented with nonorthogonal multiple access (NOMA) systems. Although NOMA benefits to such system in term of the serving users, device to device (D2D) faces the interference from normal cellular users (CUE). In particular, we derive exact formulas of outage probability to show system performance. In this article, we compare two schemes to find relevant scheme to implement in practice. The frame structure is designed with two timeslot related to uplink and downlink between the base station and D2D users. We confirm the better scheme in numerical result by considering the impacts of many parameters on outage performance.

scholarly journals Time and Power Allocation for Energy Efficiency Maximization in Wireless-Powered Full-Duplex Relay Systems

2019 ◽  
Vol 11 (10) ◽  
pp. 205
Author(s):  
Song ◽  
Ni ◽  
Han ◽  
Qin ◽  
Dong
Keyword(s):  
Energy Efficiency ◽  
Energy Harvesting ◽  
Power Allocation ◽  
Full Duplex ◽  
Optimal Time ◽  
Wireless Power ◽  
Time Switching ◽  
Relay Systems ◽  
Single Antenna ◽  
Wireless Power Supply

In this paper, we propose an optimal time and power allocation scheme in a wireless power supply full-duplex (FD) relay system, where we consider the number of relay antennas in the energy harvesting stage. At the same time, the energy efficiency optimization problem of the system is structured, where optimization issues related to time allocation factors and power allocation are established. For the FD dual-antenna and the FD single-antenna energy harvesting system, energy efficiency function is proven to be a concave function over the time-switch factor, and the optimal time-switching factor is theoretically obtained using the Lambert function. Then, according to the given value range of the optimal time switching factor, the optimal power distribution scheme is obtained by analyzing the derivative function of the system energy efficiency and using the properties of the Lambert function. The time-switching factor and transmission power are optimally selected at the wireless power supply FD relay. Results reveal that the performance of energy efficiency of the dual-antenna energy harvesting at the FD relay outperforms that of the single-antenna. Moreover, our results demonstrate that FD relay systems always substantially boost the energy efficiency compared with half-duplex (HD) relay systems.

scholarly journals Improving Performance of Far Users in Cognitive Radio: Exploiting NOMA and Wireless Power Transfer

Energies ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 2206 ◽  
Author(s):  
Minh-Sang Van Nguyen ◽  
Dinh-Thuan Do ◽  
Miroslav Voznak
Keyword(s):  
Cognitive Radio ◽  
Energy Harvesting ◽  
Power Allocation ◽  
Signal To Noise Ratio ◽  
Selection Strategy ◽  
Amplify And Forward ◽  
Outage Performance ◽  
Main Observation ◽  
Relaying Systems ◽  
Single Relay

In this paper, we examine non-orthogonal multiple access (NOMA) and relay selection strategy to benefit extra advantage from traditional cognitive radio (CR) relaying systems. The most important requirement to prolong lifetime of such network is employing energy harvesting in the relay to address network with limited power constraint. In particular, we study such energy harvesting CR-NOMA using amplify-and-forward (AF) scheme to improve performance far NOMA users. To further address such problem, two schemes are investigated in term of number of selected relays. To further examine system performance, the outage performance needs to be studied for such wireless powered CR-NOMA network over Rayleigh channels. The accurate expressions for the outage probability are derived to perform outage comparison of primary network and secondary network. The analytical results show clearly that position of these nodes, transmit signal to noise ratio (SNR) and power allocation coefficients result in varying outage performance. As main observation, performance gap between primary and secondary destination is decided by both power allocation factors and selection mode of single relay or multiple relays. Numerical studies were conducted to verify our derivations.

scholarly journals Outage performance of downlink NOMA-aided small cell network with wireless power transfer

2021 ◽  
Vol 10 (5) ◽  
pp. 2686-2695
Author(s):  
Anh-Tu Le ◽  
Dinh-Thuan Do ◽  
Munyaradzi Munochiveyi
Keyword(s):  
Wireless Power Transfer ◽  
High Energy ◽  
Base Station ◽  
Small Cell ◽  
Power Transfer ◽  
Wireless Power ◽  
Downlink Transmission ◽  
Outage Performance ◽  
Cell Network ◽  
Small Cell Network

This article considers the outage performance of the downlink transmission for a small cell network in a heterogeneous network. Due to mobility and distribution of users, it is necessary to study massive connections and high energy efficiency for such kind of systems. To be an enabler of energy harvesting, a power beacon is helpful to support the base station to send signals to distant users, and wireless power transfer (WPT) is exploited to guarantee the data packets transmission from the power beacon to the base station. To provide massive connections, we propose a novel non-orthogonal multiple access (NOMA) technique combined with WPT to enhance outage performance and latency reduction. Furthermore, we derive outage probability (OP) to characterize the system performance. Simulation results are verified to match well between theoretical and analytical methods, and main parameters are determined to understand how they affect the proposed scheme.

scholarly journals Joint user grouping and time allocation for NOMA with wireless power transfer

2021 ◽  
Author(s):  
Mehak Basharat
Keyword(s):  
Energy Harvesting ◽  
Power Allocation ◽  
Time Allocation ◽  
Data Rate ◽  
Time Sharing ◽  
Wireless Power ◽  
5G Networks ◽  
User Grouping ◽  
Promising Solution ◽  
Information Transfers

Non-Orthogonal Multiple Access (NOMA) has recently been explored to address the challenges in 5G networks such as spectral efficiency, large number of devices, etc. Further, energy harvesting is a promising solution to address the challenges for energy efficiency in 5G networks. In this thesis, joint user grouping, power allocation, and time allocation for NOMA with RF energy harvesting is investigated. We mathematically modeled a framework to optimize user grouping, power allocation, and time allocation for energy harvesting and information transfers. The objective is to maximize data rate while satisfying the constraints on minimum data rate requirement of each user and transmit power. We adopted mesh adaptive direct search (MADS) algorithm to solve the formulated problem. The user grouping in MADS is comparable with the exhaustive search which is computationally very complex. The thesis is supported with simulation results in terms of user grouping, power allocation, user rate, and time sharing.

scholarly journals Joint user grouping and time allocation for NOMA with wireless power transfer

2021 ◽  
Author(s):  
Mehak Basharat
Keyword(s):  
Energy Harvesting ◽  
Power Allocation ◽  
Time Allocation ◽  
Data Rate ◽  
Time Sharing ◽  
Wireless Power ◽  
5G Networks ◽  
User Grouping ◽  
Promising Solution ◽  
Information Transfers

Non-Orthogonal Multiple Access (NOMA) has recently been explored to address the challenges in 5G networks such as spectral efficiency, large number of devices, etc. Further, energy harvesting is a promising solution to address the challenges for energy efficiency in 5G networks. In this thesis, joint user grouping, power allocation, and time allocation for NOMA with RF energy harvesting is investigated. We mathematically modeled a framework to optimize user grouping, power allocation, and time allocation for energy harvesting and information transfers. The objective is to maximize data rate while satisfying the constraints on minimum data rate requirement of each user and transmit power. We adopted mesh adaptive direct search (MADS) algorithm to solve the formulated problem. The user grouping in MADS is comparable with the exhaustive search which is computationally very complex. The thesis is supported with simulation results in terms of user grouping, power allocation, user rate, and time sharing.

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