Joint Design of Improved Spectrum and Energy Efficiency With Backscatter NOMA for IoT

Chi-Bao Le,Adao Silva,Dinh-Thuan Do,Heejung Yu,Nhan Duc Nguyen,Waqas Khalid,Wali Ullah Khan

doi:10.1109/access.2021.3139118

Abstract

To develop emerging transmission techniques for potential applications of Internet of Things (IoT), the system performance analysis of a cognitive radio (CR)-enabled ambient backscatter (AmBC) system will be studied in this paper with functionality of non-orthogonal multiple access (NOMA). In the proposed scheme, a base station communicates with two destinations via a designated backscatter device. It is assumed that the relay node is fitted with two different interfaces and can simultaneously collect/decode and backscatter the received source signals. Such transmission mechanism benefits to design various applications in IoT as well as wireless systems with improved performance. To exhibit system performance metrics, the outage probability and the ergodic capacity of the recipient nodes are derived analytically. Furthermore, it is shown that employing AmBC NOMA together with CR for secondary communication can significantly improve overall network performance in terms of the achievable throughput in delay-limited and delay-tolerant modes and outage probability. Numerical results show that: <i>1) The proposed system can improve the spectrum efficiency by employing both CR and NOMA techniques; 2) Compared with the orthogonal multiple access (OMA)-aided AmBC systems, the considered CR AmBC system relying on NOMA can obtain better reliability in the whole range of SNR; 3) There are error floors for the outage probability in the high SNR regime due to required target rates; 4) There exists a trade-off between system performance of IoT devices and power allocation coefficients associated with NOMA; 5) We find energy efficiency factor as evident of further improvement in such system</i>.

Highlights

Ambient backscatter communication (AmBC) has been studied as a promising technique for the implementation of passive wireless devices [1]
Remark 1: We find that expression of outage probability for user D2 depends on values of ζ2 and ξ2 while these parameters are decided by the power allocation parameter a1 and a2
In this paper, we have proposed a cognitive AmBC non-orthogonal multiple access (NOMA) model which incorporates the advantage of CR technique to strengthen spectrum efficiency for promising low-cost IoT deployment

Summary

Introduction

Ambient backscatter communication (AmBC) has been studied as a promising technique for the implementation of passive wireless devices [1]. AmBC is considered as one of the energy-efficient and cost-effective communications technologies since it allows passive backscatter devices (BDs) that rely on ambient radio frequency (RF) carriers or incident sinusoidal carriers to modulate their signal without using a power-hungry and expensive RF transmitter [2]- [5]. Ambient backscatter nodes are able to operate without any specific supply/power storage infrastructure. The ambient backscatter transmitter (ABTx) backscatters the received RF information from an ambient source [6].

Objectives

Results

Conclusion