Three-Dimensional Generalized Spatial Modulation for Ambient Backscatter Communication

In this letter, a three-dimensional generalized spatial modulation for ambient backscatter communication (3D-GSM-AmBC) is proposed. A 3D constellation and antenna selection method are jointly designed so that the minimum Euclidean distance (MED) among the backscatter signals is significantly increased. Thus, the proposed scheme can achieve superior performance while providing high spectral efficiency. Furthermore, a threshold and Euclidean metric calculation rule-based joint low-complexity detector (JLCD) is proposed to reduce the complexity of ML detector. Performance analysis and simulation results show that 3D-GSM-AmBC outperforms some of the related schemes.

I. Introduction

Ambient backscatter communication (AmBC) emerging as a low-energy communication technology has a great potential for Internet of Things (IoT) and 6G applications [1], [2]. AmBC leverages the ambient RF signals such as broadcast TV or WiFi signals to transmit its own information [3]. In the presence of incident signals, AmBC devices achieve backscattering by changing antenna impedance [4]. AmBC neither requires scarce and expensive dedicated spectrum, nor requires dedicated power infrastructure, reducing costs and improving energy efficiency.