Interference Analysis of Bi-static Backscatter Communication System: Two Backscatter Devices

Ambient backscatter communication (AmBC) systems utilize existing ambient radio frequency (RF) signals to establish an indirect communication link between a transmitter (TX) and a receiver (RX). Backscatter devices (BDs) modulate their useful information on the incoming ambient signal emitted by the TX, as such their range is usually a very short event when only one BD is considered. This paper aims to analyze the impact of the interference generated due to the presence of another BD in a bi-static backscatter communication system. It is observed from the simulation results that the received signal degradation is mostly due to the cross interference of the other BD, which can be mitigated using successive interference cancellation (SIC) techniques. The level of both cross interference and self interference is significant when the interfering BD is located close to the target BD or the receiver. Therefore, AmBC systems can support more than one BD in an environment as long as the BDs are placed more than a wavelength apart from each other and RX.