Intelligent Reflecting Surface-Assisted Bistatic Backscatter Networks: Joint Beamforming and Reflection Design

Bistatic backscatter communication (BackCom) allows passive tags to transmit over extended ranges, but at the cost of having carrier emitters either transmitting high powers or being deployed very close tags. In this paper, we examine how presence an intelligent reflecting surface (IRS) could benefit bistatic BackCom system. We study power minimization problem emitter, where its beamforming vector is jointly optimized with IRS phase shifts, whilst guaranteeing a required performance. A unique feature in system setup multiple reflections experienced by signals traveling from emitter reader, which renders optimization highly nonconvex. Therefore, propose algorithms based on minorization-maximization and alternating techniques obtain approximate solutions for joint design. also low-complexity successive individual shifts. Our results reveal considerable savings both single-tag multi-tag systems, even moderate sizes, may be translated significant range improvements using original reduction reliance located range.