Performance Evaluation of Relay Selection Schemes in Beacon-Assisted Dual-Hop Cognitive Radio Wireless Sensor Networks under Impact of Hardware Noises.

Tran Hieu,Seong Choi,Le Dung,Tran Duy

doi:10.3390/s18061843

Abstract

To solve the problem of energy constraints and spectrum scarcity for cognitive radio wireless sensor networks (CR-WSNs), an underlay decode-and-forward relaying scheme is considered, where the energy constrained secondary source and relay nodes are capable of harvesting energy from a multi-antenna power beacon (PB) and using that harvested energy to forward the source information to the destination. Based on the time switching receiver architecture, three relaying protocols, namely, hybrid partial relay selection (H-PRS), conventional opportunistic relay selection (C-ORS), and best opportunistic relay selection (B-ORS) protocols are considered to enhance the end-to-end performance under the joint impact of maximal interference constraint and transceiver hardware impairments. For performance evaluation and comparison, we derive the exact and asymptotic closed-form expressions of outage probability (OP) and throughput (TP) to provide significant insights into the impact of our proposed protocols on the system performance over Rayleigh fading channel. Finally, simulation results validate the theoretical results.

Highlights

In wireless sensor networks (WSNs), energy is one of the most critical resources because sensors are often low-cost, energy-constrained, resource-constrained nodes [1,2]
A set of numerical results are presented to illustrate the performances of three proposed energy harvesting (EH) DF cooperative relay selection schemes under the interference constraints of multiple
The network nodes are arranged in Cartesian coordinates, where the node S is located at the origin

Summary

Introduction

In wireless sensor networks (WSNs), energy is one of the most critical resources because sensors are often low-cost, energy-constrained, resource-constrained nodes [1,2]. [5,6,7], radio frequency (RF) energy harvesting (EH) has recently become a promising technique for WSNs since it allows information and energy to be transmitted simultaneously [8,9,10,11,12,13]. In [8], the authors first dealt with the fundamental trade-off between transmitting energy and information at the same time over single input single output (SISO) additive white Gaussian noise (AWGN) channels. Based on these pioneering works, Refs. [9,10] proposed more practical designs, by assuming that the receivers are capable of performing EH and information decoding separately

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Conclusion