Дисертації з теми "Energy harvesting relays"
Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями
Ознайомтеся з топ-19 дисертацій для дослідження на тему "Energy harvesting relays".
Біля кожної праці в переліку літератури доступна кнопка «Додати до бібліографії». Скористайтеся нею – і ми автоматично оформимо бібліографічне посилання на обрану працю в потрібному вам стилі цитування: APA, MLA, «Гарвард», «Чикаго», «Ванкувер» тощо.
Також ви можете завантажити повний текст наукової публікації у форматі «.pdf» та прочитати онлайн анотацію до роботи, якщо відповідні параметри наявні в метаданих.
Переглядайте дисертації для різних дисциплін та оформлюйте правильно вашу бібліографію.
Elmorshedy, Lina. "RF energy harvesting in a decode-and-forward wireless relay network." Thesis, University of British Columbia, 2016. http://hdl.handle.net/2429/57607.
Повний текст джерелаApplied Science, Faculty of
Electrical and Computer Engineering, Department of
Graduate
Arab, Loodaricheh Roya. "Resource allocation in wireless systems with relay-based cooperation and energy harvesting." Thesis, University of British Columbia, 2015. http://hdl.handle.net/2429/55917.
Повний текст джерелаApplied Science, Faculty of
Electrical and Computer Engineering, Department of
Graduate
Li, Ziyi. "Wireless-Powered Communication with Energy Accumulation." Thesis, The University of Sydney, 2016. http://hdl.handle.net/2123/16123.
Повний текст джерелаNguyen, K. G. (Kien-Giang). "Energy-efficient transmission strategies for multiantenna systems." Doctoral thesis, Oulun yliopisto, 2019. http://urn.fi/urn:isbn:9789526222677.
Повний текст джерелаTiivistelmä Langattomat verkot ovat kehittyneet nopeasti räjähdysmäisesti kasvavan dataliikenteen mahdollistamiseksi, minkä seurauksena energiankulutus on kasvanut kestävän kehityksen rajat ylittävällä tavalla. Siksi energiatehokkuudesta (EE, energy efficiency) on tullut uusien langattomien verkkojen keskeinen suunnittelukriteeri vastauksena kasvavaan huoleen kasvihuonepäästöistä ja kestävästä talouskasvusta. Väitöskirjassa tutkitaan moniantennisten langattomien järjestelmien energiatehokkaita tiedonsiirtostrategioita. Tavoitteena on kehittää lineaarisia keilanmuodostustekniikoita, jotka maksimoivat energiatehokkuuden mitattuna bitteinä joulea kohden, keskittymällä kolmeen kiinnostavaan vaihtoehtoon, joita ovat koordinoitu monisolujärjestelmän lähetys laskevalla siirtotiellä, pilvipohjainen radioliityntäverkko (C-RAN, cloud radio access network), jossa laskentayksikön ja varsinaisen radiolähettimen välinen yhteys (fronthaul) on rahoitettu, ja usean parin relejärjestelmiin, joissa releet toimivat paristoilla. Työn pääpaino on alioptimaalisissa, mutta käytännöllisesti tehokkaissa optimointimenetelmissä. Pääpaino on alioptimaalisissa mutta tehokkaissa optimointitavoissa, jotka ovat kiinnostavia käytännön toteutuksen näkökulmasta. Ensiksi tarkastellaan tasapuolisen energiatehokkuuden saavuttamista monisoluisessa laskevan siirtotien moni-tulo yksi-lähtö (MISO, multiple-input single-output) -järjestelmässä. Koordinoitu keilanmuodostus on suunniteltu erityisesti maksimoimaan energiatehokkuuden minimitaso kaikilla tukiasemilla. Tarkemmin sanottuna pyritään maksimoimaan huonoin energiatehokkuus solmujen välillä, kun käytetään yhteistoiminnallista keilanmuodostusta. Muodostetun ongelman ratkaisemiseksi ehdotetaan edistyksellisiä iteratiivisia menetelmiä käyttämällä sekä keskitettyjä että hajautettuja ratkaisuja. Laskevan siirtosuunnan fronthaul-rajoitetussa C-RAN-järjestelmässä selvitetään verkonlaajuista energiatehokkuutta keilanmuodostuksen ja palvelevan tukiaseman yhteisoptimoinnilla. Tässä käytetään verrattain realistista tehonkulutusmallia, joka sisältää datanopeudesta riippuvan prosessointitehon ja epälineaarisen tehovahvistimen (PA, power amplifier) hyötysuhteen. Jotta saadaan käsitys ongelman optimaalisesta suorituskyvystä, siihen kehitetään globaalisti optimaalinen menetelmä. Lisäksi ehdotetaan kaksi käytännöllisempää iteratiivista menetelmää, jotka saavuttavat lähes optimaalisen suorituskyvyn. Lopuksi keskitytään monen parin vahvista-ja-välitä eteenpäin (AF. amplify and forward) verkkoon, jossa aikajakokytkentää käyttävät energiarajoitetut toistimet keräävät energiaa käyttäjien lähettämistä radiosignaaleista. Jotta saavutetaan EE:n oikeudenmukaisuus kaikkien parien välillä, parametrit, kuten käyttäjien lähetysteho, toistimen keilanmuodostus, ja energiankeräysaika suunnitellaan yhdessä. Tässä tutkitaan nopeusriippuvaisen piirin tehon, epälineaarisen tehovahvistimen hyötysuhteen ja epälineaaristen energiankeräyspiirien tehon vaikutusta suorituskykyyn
Sudhakar, Modem. "Optimization of networks with energy harvesting relays." Thesis, 2018. http://localhost:8080/xmlui/handle/12345678/7582.
Повний текст джерелаTe-LinKung and 孔德琳. "Relay Selection and Block Scheduling for Energy Harvesting Relays Based on Time Division Multiplexing." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/05259961840669336141.
Повний текст джерела國立成功大學
電腦與通信工程研究所
103
Energy harvesting (EH) is an attractive solution to prolong the lifetime of wireless devices. As the replacement of traditional battery-powered relay nodes, EH relays extract energy from the signal of the source node and use the harvested energy to perform information relaying, enabling a self-sustainable cooperative network. To use the harvested energy efficiently which is limited due to the energy loss by wireless channel impairment and RF-DC conversion, it is important to properly schedule the two tasks for relays, namely information and EH, within a transmission block. In this thesis, we investigate block scheduling and relay selection problems in a cooperative networks with EH relays. In terms of block scheduling, we consider two variants of time division multiplexing, including partial time reuse and full-duplex scheduling. In terms of relay selection, we propose a relay selection scheme where selected max-max relay selection (S-MMRS) considers both the source-relay channel for EH and the relay-destination channel for information relaying in selecting the cooperating relay. To evaluate the performance of the proposed S-MMRS, we theoretically analyze the outage probability and the throughput and the simulation results are presented to verify the analysis accuracy and demonstrate the impact of system parameters to the proposed relay selection scheme.
Lin, Yean-ping, and 林晏平. "Lifetime Maximization in AF Cooperative Networks with Energy-Harvesting Relays." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/8c2etv.
Повний текст джерела國立中山大學
通訊工程研究所
103
In this thesis, we consider AF cooperative networks with multiple radio frequency energy-harvesting (RFEH) relays, and investigate power allocation and relay selection strategies to prolong the network lifetime since relays are battery-powered with limited energy. Through cooperation among multiple relays, reliability and transmission rate of cooperative networks are enhanced by exploiting spatial diversity. If relays rely on wireline power supplies, implementation cost must increase and mobility is lacked. Therefore, we consider relays apply RFEH technology to harvest energy by transferring ambient RF signal into electrical energy, so that they can be self-sustained. Consequently, the network lifetime can be further prolonged. In this thesis, we investigate relay selection strategies to choose one relay to forward messages while the others perform energy harvesting. Those selection strategies aim to minimize the loss of energy dissipation, reducing wasted energy and increase the average harvested energy, in order to prolong the network lifetime. In this thesis, we define network lifetime based on the outage performance of the network. Specifically, if outage probability of network is lower than a threshold, the system is treated as &;quot;well-functioned&;quot;, and the network lifetime is defined as the longest period in which network is well-functioned. From the expression of outage probability, network lifetime is related to the residual energy of relays.Compares with existing relay selection strategies which take Channel State Information(CSI),Residual Energy Information(REI), and/or Harvested Energy Information(HEI) into account, we proposed a novel relay selection scheme based on opportunity cost of each choice. Because the proposed scheme properly exploits CSI, REI, and HEI, the proposed scheme outperforms others with stringent outage requirement. Moreover, since all relay selection strategies require simply local CSI, REI, and HEI, they can be accomplished in a distributed manner through opportunistic carrier sensing without extra overhead.
Yu-HsienLi and 李郁賢. "Cooperative Relay Selection Scheme based on Wireless Energy Harvesting." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/15346663975401734418.
Повний текст джерела國立成功大學
電腦與通信工程研究所
102
The use of energy harvesting (EH) nodes as cooperative relays is a promising and emerging solution for energy limited wireless systems, rendering the network self-sustaining with significantly prolonged lifetime. In this thesis, we consider multiple EH relay nodes harvesting energy from the radio frequency (RF) signal received from the source and use that harvested energy to forward the source information to the destination. Unlike conventional wireless nodes relied on fixed power supplies, EH relays may not be permanently available to assist the source transmission due to the limited energy conversion efficiency, the mismatch between the charging and discharging profiles, and the finite energy storage capacity. Our objective is to improve the reliability of EH relays by properly selecting one relay to perform data forwarding while the remaining relays perform energy harvesting. We propose the ``battery-aware relay selection (BARS)', which jointly considers the channel condition and the buffer status for relay selection. The outage probability of the proposed scheme is analyzed based on a Markov chain model. Simulations are performed to validate the analysis accuracy. The proposed scheme is compared with the ``CSI-based relay selection scheme', which selects the cooperating relay only based on the channel condition. Through numerical results, we show that the CSI-based scheme suffers error floor while the propose BARS scheme can achieve the full diversity order equal to the number of relays without the need of fixed power cables.
Mashiri, Tatenda Kuwarika. "Relay selection in massive MIMO wireless energy harvesting cognitive networks." Thesis, 2020. https://hdl.handle.net/10539/31118.
Повний текст джерелаIn recent years, there has been an explosive growth in bandwidth-hungry wireless devices and applications which has, in turn, caused a strain on the provisions of the present electromagnetic spectrum. Several technologies have been studied and implemented in the quest to try and alleviate this growing scarcity of the spectrum. This work, therefore, tries to address some of these challenges by looking at spectrum utilisation techniques and how optimal they can be implemented to improve the spectral efficiency and overall system performance. This research seeks to investigate the sum-rate and outage performance of an energy harvesting cognitive massive multiple-input multiple-output (MIMO) multi-relay assisted network with underlay spectrum sharing. The secondary network is permitted to opportunistically access the licenced primary network frequency band provided that the intra-cell interference imposed on the primary base station due to concurrent secondary network transmissions does not exceed the pre-set interference temperature and hence maintain the quality-of-service (QoS) requirements of the primary network. The introduction of relays improves the system performance by increasing the network coverage and this research analyses the performance of the cognitive relay networks by looking at (i) the effect of primary user interference on the relay and subsequently relay selection, (ii) the outage probability of the secondary network being assisted by an amplify-and-forward (AF) relay and (iii) the impact of the number of relay antennas and the number of relays. The power-constrained secondary network nodes harvest energy from concurrent transmissions of the energy sufficient primary users. A time switching protocol is implemented in this work for energy harvesting and closed-form expressions for the harvested energy and achievable sum-rate are derived. To that end, this research seeks to quantify the trade-off between the achievable sum-rate of the network and the harvested energy. The primary base station and secondary destination employ zero-forcing detection and performance is investigated over Rayleigh fading
CK2021
Chiu, Han-Chiuan, and 邱翰銓. "Precoding Design in Two-Way Cooperative System with Energy Harvesting Relay." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/64785606245180005933.
Повний текст джерела國立中山大學
電機工程學系研究所
102
Due to rapid development of mobile communications, radio-frequency signals are surrounded in our environment. Besides conveying information, the ambient radio-frequency signal has gradually been utilized for energy harvesting. Radio Frequency energy harvesting begins from the fact that people gradually rely on mobile applications, such as communication apps., picturing software, and games, in their daily life. However, these applications are energy consuming. Although these devices can be charged through portable power bank, the energy stored in the power bank is still limited, which leads to inconvenience when the power bank is in outage. To provide further convenience, RF energy harvesting has been developed to avoid mobile devices suffering power outage by gathering energy from from the ambient radio frequency signals and transferring into electricity. Furthermore, simultaneously processing information and harvesting energy from the RF signal has been studied extensively in recent years. In this thesis, we will employ this technique in two-way amplify-and-forward relay system, where two users exchange information under assistance of an energy-harvesting relay node. Specifically speaking, transmission power of the relay node depends on the electrical energy harvested in previous phase. We assume that the relay node is equipped with two antennas, while the users are equipped with a single antenna. With perfect channel information, the relay node can coherently combines the signals received at two antennas, so that the relay node is able to gather more energy. In this thesis, we proposed a joint design of a precoding matrix and power-slitting ratios for the relay node to maximize the sum-rate of two users under a constraint that the transmission power of the relay node cannot exceed the harvested energy. However, this optimization problem is neither convex nor concave, and it can’t be solved by CVX tool. Thus, we divide the problem into two sub-problems to approach a locally-optimal solution of the precoding matrix and power-splitting ratios in an iterative manner. Specifically, we employ gradient algorithm to obtain power-splitting ratios with initial value obtained by exhaustively searching over a rough grid. Then, the beamforming matrix is obtained using power iteration algorithm. After several iterations, two subproblems get converged and we can find the set of suboptimal solutions. It shows through simulation results that the proposed scheme can effectively improve the spectrum efficiency of the system.
Ho, Kuei-yu, and 何奎諭. "Design and Simulation of Optimal Transmission Policies for Energy Harvesting Relay Networks." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/kngvwh.
Повний текст джерела國立中央大學
通訊工程學系
103
Toward a green communication, the scheduling and the optimal power allocation are two key approaches to address the problem of inadequate resources in the future wireless communications. The existing schemes are based on fixed and stochastic energy and they didn’t take the energy causality constraints into account. In this work, we focus on the optimal power control schemes under the uncertainty of harvested energy, and we also consider both half-duplex and full-duplex protocols to transmit the data. In this research, we consider online case and offline case with an energy harvesting (EH) sources communicates with the destination via an EH decode-and-forward relay. In online case, we formulate the problem as a Markov decision process to find the best policies. In the offline case, we use optimal form to solve the problem and propose a suboptimal simplifying the complexity. The main contribution of this research is to find the optimal policies that maximize the throughput and minimize the outage probability under different situations.
Sirojuddin, Ahmad, and 丁與智. "Precoding Design in Two-Way Multi-Antenna Relay System with Energy Harvesting." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/n62bjk.
Повний текст джерела國立中山大學
電信工程國際碩士學位學程
107
A system with two single-antenna users that want to exchange their data via a multi-antenna relay has been investigated in this work. After the two users send their data, the relay performs a signal processing so that the sum-rate is maximum. After deriving the SNR equation, we optimize three parameters to achieve the goal: phase rotating factor, precoder, and power splitting ratio. Since the joint optimization over these three variables is difficult, then we optimize them separately. The purpose of optimizing the phase rotating factor is to get the harvested power as high as possible that will be used for data broadcasting by the relay. We develop an iterative algorithm that has a low computational complexity and fast in convergence. Besides, we find a near optimum point that can be calculated analytically. The purpose of optimizing the precoder is to get the rate as high as possible. Since the conventional method finding the first derivation equals to zero cannot be implemented to find an optimum precoder, we finally use the gradient descent method that is developed with an initial point optimization that is close with the actual optimal point. We consider these three methods to find an optimal solution for the power splitting ratio. It has been analyzed that these three methods have their own positive and negative sides.
Uei-ChiehNiu and 牛威捷. "Relay Selection Based on Partial CSI for Energy Harvesting in MIMO Systems." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/69cby3.
Повний текст джерелаCiao-HanLin and 林巧涵. "Relay Selection in Energy-Harvesting Systems with Packet Storage and Finite Battery." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/5tnkh3.
Повний текст джерела國立成功大學
電腦與通信工程研究所
107
In this thesis, we study the relay selection problem for a buffer-aided and energy harvesting cooperative system. A number of relays harvest energy from the source signal and one relay are selected to forward the source signal using the harvested energy. Since the harvested energy is often weak, the best practice is to accumulate the harvested energy by storing it into the rechargeable battery. With the aid of energy and data storage, both limited in size, an important question is how to determine the action of each relay, namely receiving data or forwarding the source signal. A relay selection scheme, called dual buffer relay selection (DBRS) is proposed considering the data buffer, energy buffer and channel status simultaneously. To evaluate the performance of DBRS, theoretical analysis based on Markov chain model is performed. Simulation results are presented to validate the analysis accuracy and get insights into the system performance subject to numerous key parameters.
Zhang, Lin-Wei, and 張凌瑋. "Design and Simulation of Transmission Policies for Cognitive Relay Networks with Energy Harvesting." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/g3qrtx.
Повний текст джерела國立中央大學
通訊工程學系
103
Cooperative Spectrum Sharing (CSS) is proposed as a solution for the inefficient utilization of the spectrum. In CSS of cognitive-radio networks, primary licensed user (PU) with poor channel condition (between its transmitter and receiver) can achieve a higher data rate by using a secondary unlicensed user (SU) as a relay. In return, the primary user possibly decides to lease part of its spectrum resource to secondary users in exchange for appropriate remuneration. The key point of CSS is how the PU and SU agree on the cooperative transmissions and resource allocations. In previous schemes, they are propose on the transmission policy with unconstrained energy. However, we focus on wireless sensor networks with energy harvesting and propose a method between PU and SU ‘s transmits policies in CSS. In our study, we formulate the problem as a Markov Decision Process (MDP) framework by which the channel states, battery conditions and harvested process are stochastic. Moreover, we also consider the condition without information of transition probability. In this case, we use the Q-learning algorithm to find the optimal transmission policies .Finally, we compare the performance of our scheme with others.
CHIU, MIN-HSIANG, and 邱民翔. "On Outage Analysis and Optimization for Full-Duplex Relay Networks with Energy Harvesting." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/fe4sa5.
Повний текст джерела國立中央大學
通訊工程學系
107
This paper discusses the outage performance of full-duplex relay channel using amplify-and-forward(AF) relay protocol with energy harvesting(EH) and compare with its optimum one. Previous works almost focused on that destination treated the self-interference signal as interference only, so in that works they wanted to eliminate self-interference(SI) signal. We provide a system model with make self-interference signal assist information decoding at the destination. At the relay node, the received signals, including self-interference, are split according to a power ratio for information processing (IP) and energy harvesting, respectively. We derive an approximate, yet accurate, closed-form expression for the end-to-end outage probability and optimum one. In addition, the processing delay is larger than one in practice, the proposed close-form outage probability expression is still valid. Finally, we corroborate our theoretical results with simulations in different situations. The results indicate that the proposed system model with optimization can outperforms system with fixed power splitting method.
Benkhelifa, Fatma. "Towards Perpetual Energy Operation in Wireless Communication Systems." Diss., 2017. http://hdl.handle.net/10754/626219.
Повний текст джерелаSarma, Siddhartha. "Resource Allocation in Wireless Networks for Secure Transmission and Utility Maximization." Thesis, 2016. http://etd.iisc.ac.in/handle/2005/3123.
Повний текст джерелаSarma, Siddhartha. "Resource Allocation in Wireless Networks for Secure Transmission and Utility Maximization." Thesis, 2016. http://hdl.handle.net/2005/3123.
Повний текст джерела