Hoang-Sy Nguyen

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.

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hybrid time switching-based and power splitting-based relaying protocol in wireless powered communication networks with outdated channel state information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 Unlike most previous works, we further focus on the impact of outdated channel state information (CSI) in WPCN.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.

Impact of hardware impairments for power splitting relay with wireless information and EH

In this paper, the research is about analyzing the effect of hardware impairments at the relay node in the cooperative networks which base on amplifying and forwarding. Importantly, in respected to the level of hardware impairments for Rayleigh fading channels. In addition, in term of the throughput which depends on the antenna noise, sources transmission power and the transmission rate, the systems overall performance is also evaluated. Lastly, the systems design with the acceptable impairment of hardware in physical which can ensure the communications quality is proposed by verifying the analysis through the Monte-Carlo simulations result.

On the Performance of Decode-and-Forward Half-Duplex Relaying with Time Switching Based Energy Harvesting in the Condition of Hardware Impairment

In this paper, the outage performance and system throughput of a decode-and-forward half-duplex relay network, in which the relay node is equipped with time switching based energy harvesting capability, are derived rigorously. The analytical results provide theoretical insights into the effect of various system parameters, such as time switching factor, source transmission rate, transmitting-power-to-noise ratio to system performance. Our analysis is confirmed by Monte-Carlo simulation, and can serve as a guideline to design practical energy-harvested relaying systems.

Opportunistic Multiple Relay Selection Schemes in both Full-Duplex and Half-Duplex Operation for Decode-and-Forward Cooperative Networks

An efficient technique used to prolong the lifetime of energy-constrained networks is energy harvesting (EH). In this paper, we investigate and develop the energy allocation methods for the relaying networks, in which opportunistic multiple relay selection schemes with both the full-duplex (FD) and half-duplex (HD) scheme for both EH and non-EH in decode-and-forward (DF) relaying mode. In addition, there are two policies proposed in this paper: (1) Max-Min with Self Interference Relay Selection (MMSI); (2) Max-Min Relay Selection (MMSR) are depicted for both EH and Non-EH relaying modes. Particularly, we derive closed-form expressions of outage probability to analyze the performance of systems. In addition, we propose the impact of self-interference on both policies to provide a practical insight. The results in numerical analysis reveal that the proposed MMSI scheme outperforms the MMSR mode in terms of outage probability.

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.

Design of energy harvesting protocol for relay mobile node in WLAN

In this paper, we propose the balanced time power switching based relaying (TPSR) protocol for energy harvesting enabled mobile node in WLAN called energy harvesting cooperative networks (EHCN). Specifically, we develop outage and throughput performance characterizations in term of energy harvesting efficient factor in the proposed scheme. It is shown that the optimal throughput of the EHCN is critically dependent on the threshold signal-to-noise (SNR) value. 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 enabled WLAN.

Hybrid full-duplex/half-duplex relay selection scheme with optimal power under individual power constraints and energy harvesting

Abstract In practice, full-duplex (FD) transmission achieves better system outage performance than that of half-duplex (HD) transmission but suffers from strong self-interference (SI). In this paper, we provide performance analysis of relay selection (RS) schemes in multi-relay wireless networks, where we obtain the exact and approximate closed-form expressions for outage probability (OP) in the high signal-to-noise ratio (SNR) regime over independent and identically distributed (i.i.d.) Rayleigh fading channels in three proposed optimal RS schemes, i.e., HD deploying maximal ratio combine (HDMRC) and FD deploying joint decoding (FDJD) and hybrid FD/HD relaying transmission scheme (HTS). Most importantly, these schemes operate in two proposed optimal power supply policies so-called optimal power under the individual power constraints (OPIPC) and optimal power with energy harvesting ability (OPEHA). Additionally, asymptotic expressions in high SNR regime are given to help gain better insights on the system performance. It is also shown that the proposed HTS scheme outperforms HDMRC and FDJD schemes in terms of outage performance, where OPEHA is better than OPIPC under the impact of SI. Besides that, HTS RS scheme significantly decreases the power consumption which helps enhance energy efficiency. The validity of the proposed analyses is proven by simulations.

Wireless powered D2D communications underlying cellular networks: design and performance of the extended coverage

ABSTRACT Because of the short battery life of user equipments (UEs), and the requirements for better quality of service have been more demanding, energy efficiency (EE) has emerged to be important in device-to-device (D2D) communications. In this paper, we consider a scenario, in which D2D UEs in a half-duplex decode-and-forward cognitive D2D communication underlying a traditional cellular network harvest energy and communicate with each other by using the spectrum allocated by the base station (BS). In order to develop a practical design, we achieve the optimal time switching (TS) ratio for energy harvesting. Besides that, we derive closed-form expressions for outage probability, sum-bit error rate, average EE and instantaneous rate by considering the scenario when installing the BS near UEs or far from the UEs. Two communication types are enabled by TS-based protocol. Our numerical and simulation results prove that the data rate of the D2D communication can be significantly enhanced.

Two-way relay networks with energy harvesting and information transfer: Throughput performance with distance allocation

In this paper, we analyse the performance analysis for two and three time slot transmission schemes (2TS and 3TS) for two-way Amplify-and-Forward (AF) relaying networks which are developed by wireless power and data transfer, where the energy harvesting (EH) relay node helps interchange information between two nodes. We derive the throughput and the approximate expressions of outage probability of the 2TS, 3TS transmission schemes and compare these results with the distance allocation between source node to relay and relay to destination node, and the large scale path loss in order to observe throughput performance. It is noted that these transmission schemes can significantly enhance the system performance.