Backscatter Communication with Selective FSK Modulation

Backscatter communication (BackCom) is known as a low-power wireless communication technology that utilizes radio frequency signal reflections instead of actively generating them. This paper introduces a novel selective Frequency Shift Keying (SFSK) modulation scheme for BackCom, aiming to simplify tag design while ensuring equivalent decoding performance at the receiver compared to the conventional pseudo-FSK method employed in backscatter tags. Knowing that the transmission range is the limitation of a passive BackCom system, we focus on maximizing the distance between the emitter and tag by optimizing the reflection coefficients. To address the non-convex nature of this optimization problem, we propose a convex approximation technique alongside an algorithm to obtain the optimized solution. Simulation results illuminate the maximum distance with the optimized reflection coefficients in various BackCom system environments and operational requirements.