Joint spectral efficiency optimization of uplink and downlink for massive MIMO-enabled wireless energy harvesting systems

AbstractThis paper investigated the spectral efficiency (SE) in massive multiple-input multiple-output systems, where all terminals have no fixed power supply and thus need to replenish energy via the received signals from the base station. The hybrid wireless energy harvesting (EH) protocol is applied for each terminal, which can switch to either existing time-switching (TS) protocol or power-splitting (PS) protocol. Based on the hybrid wireless EH protocol, a general system model is developed, which can switch to either only uplink data transmission or only downlink data transmission. As a result, a general analytical framework is formulated. Then, closed-form lower bound expressions on SE for each terminal are obtained on the uplink and downlink, respectively. According to these expressions, the joint SE of uplink and downlink maximization problem is designed with some practical constraints. As the designed optimization problem is non-linear and non-convex, it is hard to solve directly. To provide a solution, an iteration algorithm is proposed by utilizing one-dimensional search technique and successive approximation method based on geometric program. Additionally, the convergence and complexity of the proposed algorithm are discussed as well. Finally, the feasibility of the proposed algorithm is analyzed by simulations. Numerical results manifest that the proposed algorithm can provide good SE by optimizing relevant system parameters, and the system model can help to discuss the TS, PS or hybrid protocol for only uplink data transmission, only downlink data transmission or joint data transmission of uplink and downlink in the considered system.

Download Full-text

Joint Spectral Efficiency Optimization of Uplink and Downlink for Massive MIMO Enabled Wireless Energy Harvesting Systems

10.21203/rs.3.rs-77518/v1 ◽

2020 ◽

Author(s):

Wenfeng Sun ◽

Chen Liu ◽

Mujun Qian ◽

Yan Chen ◽

Shu Xu

Keyword(s):

Energy Harvesting ◽

Spectral Efficiency ◽

Mimo Systems ◽

Multiple Input Multiple Output ◽

Base Station ◽

Maximization Problem ◽

Iteration Algorithm ◽

Successive Approximation Method ◽

Harvesting Systems ◽

Wireless Energy Harvesting

Abstract This paper proposes a unified system model and uses a general wireless energy harvesting (EH) protocol in massive multiple-input multiple-output (MIMO) systems, in which the terminals have no fixed power supply and thus need to replenish energy via the received signals from the base station (BS). On the downlink, the BS delivers radio frequency (RF) signals to all terminals and each terminal coordinates the processes of EH and information decoding (ID) with wireless EH protocol. On the uplink, a fraction of the harvested energy is used for uplink pilot transmission and the remaining fraction is used for uplink data transmission. Closed-form lower bound expressions for each terminal are first obtained on the uplink and downlink, respectively. Based on these expressions, we then formulate the joint spectral efficiency (SE) of uplink and downlink maximization problem with some practical constraints. As the formulated optimization problem is non-linear and non-convex, it is hard to solve directly. To provide a solution, an iteration algorithm is proposed by utilizing one-dimensional search technique and successive approximation method based on geometric program (GP). Additionally, the convergence and complexity of the proposed algorithm are discussed as well. Finally, the feasibility of the proposed algorithm and analytical results are demonstrated by extensive computer simulations.

Download Full-text

Robust Beamforming Design for Secure V2X Downlink System with Wireless Information and Power Transfer under a Nonlinear Energy Harvesting Model

Sensors ◽

10.3390/s18103294 ◽

2018 ◽

Vol 18 (10) ◽

pp. 3294 ◽

Cited By ~ 5

Author(s):

Shidang Li ◽

Chunguo Li ◽

Weiqiang Tan ◽

Baofeng Ji ◽

Luxi Yang

Keyword(s):

Energy Harvesting ◽

Traffic Safety ◽

Optimization Problem ◽

Optimal Solution ◽

Base Station ◽

Power Splitting ◽

Power Transfer ◽

Vehicular Communication ◽

Downlink System ◽

Nonlinear Energy

Vehicle to everything (V2X) has been deemed a promising technology due to its potential to achieve traffic safety and efficiency. This paper considers a V2X downlink system with a simultaneous wireless information and power transfer (SWIPT) system where the base station not only conveys data and energy to two types of wireless vehicular receivers, such as one hybrid power-splitting vehicular receiver, and multiple energy vehicular receivers, but also prevents information from being intercepted by the potential eavesdroppers (idle energy vehicular receivers). Both the base station and the energy vehicular receivers are equipped with multiple antennas, whereas the information vehicular receiver is equipped with a single antenna. In particular, the imperfect channel state information (CSI) and the practical nonlinear energy harvesting (EH) model are taken into account. The non-convex optimization problem is formulated to maximize the minimum harvested energy power among the energy vehicular receivers satisfying the lowest harvested energy power threshold at the information vehicular receiver and secure vehicular communication requirements. In light of the intractability of the optimization problem, the semidefinite relaxation (SDR) technique and variable substitutions are applied, and the optimal solution is proven to be tight. A number of results demonstrate that the proposed robust secure beamforming scheme has better performance than other schemes.

Download Full-text

RF Energy Harvesting with Multiple Sources in Wireless Mesh Network

Indonesian Journal of Electrical Engineering and Computer Science ◽

10.11591/ijeecs.v10.i2.pp606-616 ◽

2018 ◽

Vol 10 (2) ◽

pp. 606 ◽

Cited By ~ 1

Author(s):

K.N Puniran ◽

Ahmad Robiah ◽

Rudzidatul Akmam Dziyauddin

Keyword(s):

Energy Harvesting ◽

Base Station ◽

Mesh Network ◽

System Throughput ◽

Power Splitting ◽

Multiple Sources ◽

Wireless Mesh ◽

Optimal Value ◽

Rf Energy ◽

Single Relay

Energy harvesting (EH) module for wireless sensor network has become a promising feature to prolong the conventional battery inside the devices. This emerging technology is gaining interest from sensor manufacturers as well as academicians across the globe. The concept of employing EH module must be cost effective and practical. In such, the use of EH module type besides RF is more realistic due to the size of the scavenger module, the availability of the resources and conversion efficiency. Most of the oil and gas plants have some drawbacks in scavenging RF from surrounding (i.e. router, Wi-Fi, base station, cell phone) due to its placement in remote area and thus limited energy sources could be a threat in this application. Multiple sources, including co-channel interference (CCI) in any constraint nodes is a feasible way of scavenging several wastes from ambient RF energy via wireless mesh topology. In this paper, a 3-node decode-and-forward (DF) model is proposed where the relay node is subject to an energy constraint. Multiple primary sources and CCI are added in the system model known as Multiple-Source and Single-Relay (MSSR). A mathematical model is derived in Time Switching Relaying (TSR) and Power Splitting Relaying (PSR) schemes to obtain an average system throughput at a destination. Numerical simulation with respect to the average throughput and EH ratio was performed and compared with the Single-Source and Single-Relay (SSSR) and ideal receiver. By applying multiple sources and CCI as an energy enhancement at the constraint node, the optimal value of EH ratio for TSR can be reduced significantly by 10% as compared to the ideal receiver whereas the optimal value of EH ratio for PSR is outweigh TSR in terms of overall system throughput.

Download Full-text

Multicast Beamforming for SWIPT in MISO Full-Duplex Systems

Nigerian Journal of Technological Research ◽

10.4314/njtr.v16i1.4 ◽

2021 ◽

Vol 16 (1) ◽

pp. 26-33

Author(s):

Alexander Akpofure Okandeji

Keyword(s):

Energy Harvesting ◽

Channel State Information ◽

Base Station ◽

Semidefinite Relaxation ◽

Full Duplex ◽

Power Splitting ◽

Power Transfer ◽

Imperfect Channel State Information ◽

Channel State ◽

State Information

This paper considers the multicast transmit beamforming and receive power splitting problem for sum transmit power minimization for a simultaneous wireless information and power transfer (SWIPT) system subject to signal-to-interference-plus-noise ratio (SINR), and energy harvesting constraints at the receiver. In particular, we consider the case of perfect and imperfect channel state information (CSI) at the base station. Using semidefinite relaxation (SDR) technique, we obtain solution to the problem with imperfect channel state information of the self-interfering channels. Keywords: Simultaneous wireless information and power transfer, channel state information, Energy harvesting, semidefinite relaxation.

Download Full-text

Dynamic Wireless Energy Harvesting and Optimal Distribution in Multipair DF Relay Network with Nonlinear Energy Conversion Model

Wireless Communications and Mobile Computing ◽

10.1155/2018/7638215 ◽

2018 ◽

Vol 2018 ◽

pp. 1-14 ◽

Cited By ~ 2

Author(s):

Syed Tariq Shah ◽

Daniel B. da Costa ◽

Kae Won Choi ◽

Min Young Chung

Keyword(s):

Energy Harvesting ◽

Energy Conversion ◽

Relay Network ◽

Power Splitting ◽

Decode And Forward ◽

Conversion Model ◽

Transmission Modes ◽

Energy Constrained ◽

Wireless Energy Harvesting ◽

Nonlinear Energy

Wireless energy harvesting has emerged as an efficient solution to prolong the lifetime of wireless networks composed of energy-constrained nodes. In this paper, we consider a multipoint-to-multipoint relay network, where multiple source nodes communicate with their respective destination nodes via intermediate energy-constrained decode-and-forward (DF) relay. The performance of two different transmission modes, namely, delay tolerant and delay nontolerant, is studied. Based on power-splitting relaying protocol (PSR), optimal energy harvesting and distribution schemes for both transmission modes are provided. In addition, for more realistic and practical analysis, we consider a nonlinear energy conversion model for energy harvesting at the relay node. Our numerical results provide useful insights into different system parameters of a nonlinear energy harvesting-based multipair DF relay network.

Download Full-text

Energy Efficiency Analysis in Modified GoF Spectrum Sensing-Based AF Relay Cooperative Cognitive Sensor Network with Energy Harvesting

Security and Communication Networks ◽

10.1155/2021/3340525 ◽

2021 ◽

Vol 2021 ◽

pp. 1-13

Author(s):

Yin Mi ◽

Guangyue Lu ◽

Wenbin Gao

Keyword(s):

Energy Efficiency ◽

Energy Harvesting ◽

Sensor Network ◽

Spectrum Sensing ◽

Closed Form Expression ◽

Initial Time ◽

Maximization Problem ◽

Power Splitting ◽

Transmission Power ◽

Af Relay

In this paper, we propose a joint sensing duration and transmission power allocation scheme to maximize the energy efficiency (EE) of the secondary user (SU) in a cooperative cognitive sensor network (CSN). At the initial time slot of the frame, the secondary transmitter (ST) performs energy harvesting (EH) and spectrum sensing simultaneously using power splitting (PS) protocol. The modified goodness of fit (GoF) spectrum sensing algorithm is employed to detect the licensed spectrum, which is not sensitive to an inaccurate noise power estimate. Based on the imperfect sensing results, the ST will act as an amplify-and-forward (AF) relay and assist in transmission of the primary user (PU) or transmit its own data. The SU’s EE maximization problem is constructed under the constraints of meeting energy causality, sensing reliability, and PU’s quality of service (QoS) requirement. Since the SU’s EE function is a nonconvex problem and difficult to solve, we transform the original problem into a tractable convex one with the aid of Dinkelbach’s method and convex optimization technique by applying a nonlinear fractional programming. The closed-form expression of the ST’s transmission power is also derived through Karush-Kuhn-Tucker (KKT) and gradient method. Simulation results show that our scheme is superior to the existing schemes.

Download Full-text

The System Performance of Half-Duplex Relay Network under Effect of Interference Noise

Journal of Advanced Engineering and Computation ◽

10.25073/jaec.201821.75 ◽

2018 ◽

Vol 2 (1) ◽

pp. 18

Author(s):

Miroslav Voznak ◽

Hoang Quang Minh Tran ◽

N. Tan Nguyen

Keyword(s):

Energy Harvesting ◽

Outage Probability ◽

System Performance ◽

Ergodic Capacity ◽

Relay Network ◽

System Throughput ◽

Power Splitting ◽

Decode And Forward ◽

Interference Noise ◽

Wireless Energy Harvesting

In recent years, harvesting energy from radio frequency (RF) signals has drawn significant research interest as a promising solution to solve the energy problem. In this paper, we analyze the effect of the interference noise on the wireless energy harvesting performance of a decode-and-forward (DF) relaying network. In this analysis, the energy and information are transferred from the source to the relay nodes in the delay-limited transmission and Delay-tolerant transmission modes by two methods: i) time switching protocol and ii) power splitting protocol. Firstly, due to the constraint of the wireless energy harvesting at the relay node, the analytical mathematical expressions of the achievable throughput, outage probability and ergodic capacity of both schemes were proposed and demonstrated. After that, the effect of various system parameters on the system performance is rigorously studied with closed-form expressions for system throughput, outage probability, and ergodic capacity. Finally, the analytical results are also demonstrated by Monte-Carlo simulation. The results show that the analytical mathematical and simulated results agree with each other. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Download Full-text