Bistatic 5G-NR Ambient Backscatter Communication: Propagation Study and Experimental Validation in Anechoic Chambers

Ambient Backscatter Communication (AmBC) has emerged as a promising low-power wireless communication technique, particularly for Internet of Things (IoT) applications. This paper presents an experimental study on a fifth-generation 5G New Radio (5G-NR) backscatter communication system operating at 3.5 GHz, focusing on bistatic configurations. Specific considerations are taken in the experimental setup to improve signal detection and minimize direct path interference (DPI). For this, a backscatter modulator prototype is developed and tested in controlled environments, including full anechoic (FA) and semianechoic (SA) chambers, to analyze its performance under various conditions. Moreover, a generic mathematical model has been proposed to predict the power budget of the whole AmBC system. This model takes into account geometrical parameters of the backscatter device (BD), i.e., distance and angles referring to the transmitter (Tx) and the receiver (Rx). The measurement results indicate significant variations in received backscatter power based on environmental factors such as reflections and antenna orientation. Experimental results are in good agreement with the theoretical model validating the systems feasibility and highlight the crucial impact of the sensor tag reflections, antenna orientation, and ground absorption on backscattered signal strength. The developed demonstrator consistently reflects a stable signal across different transmit power levels. This study provides key insights into the feasibility of 5G-NR ambient backscatter for energy-efficient wireless communication.