Dinh-Thuan Do

Energy-aware two-way relaying networks under imperfect hardware: optimal throughput design and analysis

In this paper, we propose a new formula for achieving optimal throughput in energy-aware cooperative networks with generic time and power energy harvesting protocol, namely time power switching based relaying (TPSR). Especially, this investigation analyzes the impact of imperfect hardware at the relay node and the destination node in the two-way relaying networks (TWRN). This analysis enables us to derive the closed-form expressions of outage probabilities of signal-to-noise and distortion ratio (SNDR) at the destination nodes under the effect of hardware impairments. Interestingly, the optimal policy of joint wireless information and energy transfer is designed to maximize the system throughput by finding the optimal time switching and power splitting fractions in the proposed TPSR protocol. An important achievement is that the proposed optimal design offers the maximum throughput of system when we consider the trade-off between throughput and time-power factors in energy harvesting protocol by both numerical method and simulation. Numerical results provide practical insights into the performance of energy-aware TWRN under hardware impairments. Monte-Carlo method is also deployed to corroborate the accuracy of analytical derived expressions.

Optimal Throughput Under Time Power Switching Based Relaying Protocol in Energy Harvesting Cooperative Networks

Abstract This paper propose novel protocol for energy harvesting enabled relaying networks. To evaluate performance, we investigate how the harvested power at relay node affects on signal to noise ratio, outage probability and optimal throughput. Specifically, we develop outage and throughput expression in terms of time and power factors in the proposed time power switching based relaying (TPSR) protocol. A highly accurate closed-form formula of outage probability and throughput are also derived. It is shown that the maximized throughput critically depends on optimal time switching and optimal power splitting coefficients of the proposed protocol. In addition, we compare performance of the energy harvesting protocol in optimal case together with balanced receiver at relay node. The impressive results in this work proved that proposed protocol outperforms power splitting based relaying protocol presented in the literature. The tightness of our proposed protocol is determined through Monte Carlo simulation results. Finally, our results provide useful guidelines for design of the energy harvesting relay node in cooperative networks.

Wireless Information and Power Transfer for Full Duplex Relaying Networks: Performance Analysis

Energy harvesting (EH) based on ambient radio frequency (RF) has recently become advanced method to prolong the lifetime of the wireless networks. This paper deals with energy harvesting architecture of the full duplex relaying networks. By applying time switching based relaying (TSR) protocol and Amplify-and-Forward (AF) scheme, we derive the closed-form expression of the outage probability and hence compute the optimal throughput. An important result can be seen clearly that the time fraction in TSR impacts on the optimal throughput. Finally, numerical results show an efficient relaying strategy in full duplex cooperative networks.

Imperfect channel state information of AF and DF energy harvesting cooperative networks

Wireless information and powered transfer networks (WIPT) has recently been implemented in 5th generation wireless networks. In this paper, we consider half-duplex relaying system in which the energy constrained relay node collects energy via radio frequency (RF) signals from the surrounding resources. Regarding energy harvesting protocol, we propose power time switching-based relaying (PTSR) architecture for both amplify-and-forward (AF) and decode-and-forward (DF). Especially, we reveal the analytical expressions of achievable throughput, ergodic capacity and energy-efficient in case of imperfect channel state information (CSI) for both AF and DF network. Through numerical analysis, we analyse the throughput performance, energy-efficient and ergodic capacity for different parameters, including power splitting ratio and energy harvesting time. Moreover, we also depict the performance comparison between AF and DF network with perfect and imperfect CSI. The results in numerical analysis reveal that the result of AF relaying network is less significant than DF relaying network in the various scenarios.

A new look at AF two-way relaying networks: energy harvesting architecture and impact of co-channel interference

In this paper, the performance of dual-hop amplify-and-forward (AF) two-way relaying systems is considered, where the terminals and relay are interfered by a finite number of co-channel interferers. In addition, the derived expressions are evaluated in terms of outage probability and throughput in delay-limited transmission mode. To make the analysis mathematically tractable, the unique expressions of outage probability are adopted to deal with energy harvesting protocols related to time switching and power splitting coefficients and expression of the throughput is also calculated. Based on the analytic results, this paper investigates the impact of system parameters such as energy harvesting time/power fractions, number of interferers and signal-to-noise ratio (SNR) on throughput performance. Monte Carlo simulation results are presented to prove the tightness of the proposed energy harvesting two-way relaying system.

Bidirectional Communication in Full Duplex Wireless-Powered Relaying Networks: Time-Switching Protocol and Performance Analysis

In this paper, we consider two-way full-duplex relay with energy harvesting system, in which the relay node harvests transmitted power from the two source nodes to forward signals to destinations. We also analyze the relay network model with decode-and-forward protocol for information cooperation and time switching-based relaying protocol for power transfer. In particular, the outage probability, average throughput and optimal energy harvesting time of novel scheme in simultaneous wireless information and power transfer are presented. We obtain analytic closed-form expressions for both tight bounded and asymptotic of outage probability and average throughput of system. Using numerical and analytic simulations, the performances of different situations are presented and discussed more clearly. The results show that the better performance is achieved in case of worse self-interference. As important result, the better self interference cancellation leads to superior system performance.

Maximum harvested energy policy in full-duplex relaying networks with SWIPT

Summary It is considered that energy scavenging is a promising way for source node transfer energy to powered constraint relay in cooperative networks with advantage of cost-effective maintenance and flexible deployment, which so-called simultaneous wireless information and power transfer. In this paper, relay selection for optimal wireless energy is investigated. In terms of time switching–based relaying, this paper considers the performance comparison of 3 proposed relay selection schemes, namely, (1) optimal relay selection scheme, (2) maximum harvested energy relay selection scheme, and (3) minimum self-interference relay selection. In particular, the system performance is studied intensively with regard to outage probability and throughput over Rayleigh fading channels. We also achieve the integral form for accurate expressions and closed form for approximate expressions. Finally, these analytical expressions are proved exactness according to Monte Carlo simulation.

Exploiting hybrid time switching-based and power splitting-based relaying protocol in wireless powered communication networks with outdated channel state information

ABSTRACT Wireless powered communication networks (WPCNs) have attracted much research interest in fifth generation (5G) wireless networks. With the help of WPCN, the reliability and battery life of wireless low-power devices can be enhanced. In this paper, we investigate throughput and ergodic capacity in WPCN-assisted amplify-and-forward relaying systems considering two transmission modes, including delay-tolerant and delay-limited. More importantly, we propose energy harvesting protocol so-called hybrid time switching-based and power splitting-based relaying (HTPSR) protocol in order to achieve optimal throughput. In particular, both time switching-based and power splitting-based coefficients in this scheme are considered. Unlike most previous works, we further focus on the impact of outdated channel state information (CSI) in WPCN. In order to evaluate information processing efficiency, the performance can be substantially improved by optimizing harvesting time and power coefficients of the received signal at the relay node for energy and information extraction. Thanks to Monte Carlo simulations, it is confirmed that the system performance is more sensitive to CSI estimation error, noise variance and signal-to-noise ratio which enable us in reasonable computations of HTPSR to obtain QoS requirement.

Wireless powered underlay cognitive radio network with multiple primary transceivers: Energy constraint, node arrangement, and performance analysis

Summary This paper considers a cognitive radio–assisted wireless information and power transfer system consisting of multipair of transceiver in primary network and 2-hop relaying link in secondary network. In this investigation, a decoded-and-forward–assisted relay node and power splitting protocol are deployed to obtain ability of wireless energy transfer. The relay node harvests energy from the radio frequency signals of the secondary transmitter and primary transmitters in data transmission to the destination by reusing the licensed spectrum resource. We propose 2 policies for wireless power transfer at the relay, namely, (1) multisource power transfer and (2) single-source power transfer. To evaluate performance under energy harvesting regime, we derive the closed-form outage probability expressions and achievable throughput of the secondary network in delay-limited transmission mode. In addition, we investigate the impact of various system parameters including number of primary transceivers, primary outage threshold, and position arrangement of nodes in primary transceivers on the outage performance of the proposed scheme. Furthermore, we evaluate the system energy efficiency to show trade-off metric of energy consumption and throughput. Performance results are presented to validate our theoretical derivation and illustrate the impacts of various system parameters. An important result is that the secondary network is more beneficial than harmful from the primary interference under power constraint and reasonable node location arrangement.

Impact of hardware impairments in AF relaying network for WIPT: TSR and performance analysis

In this paper, we examine amplifying and forwarding (AF) based cooperative networks and analyze the impact of hardware impairments at the relay node on optimal throughput. In particular, the outage probability performance under hardware impairments for Rayleigh fading channels is presented in case of wireless information and power transfer (WIPT) technology. In addition, we evaluate clearly the systems performance under impact of time switching factors in time switching based relaying (TSR) protocol, level of hardware impairment and energy conversion efficiency. Finally, the Monte-Carlo simulations result verifies the analysis in physical receiver with the acceptable hardware impairments level in order to approach the best quality of wireless communication.