ISAC with Backscattering RFID Tags: Beamforming and Codebook Design

2026-04-16

AI Summary

This work addresses the joint optimization of communication quality-of-service and backscatter RFID tag sensing requirements in integrated sensing and communication (ISAC) systems under a total transmit power constraint. For both single-tag and multi-tag scenarios, the study proposes a closed-form zero-forcing beamforming solution and a power-minimization-based joint beamforming design, respectively, and introduces a novel sectorized joint beamforming codebook structure. By leveraging semidefinite relaxation and generalized Benders decomposition techniques, the approach efficiently optimizes beam directions and power allocation, effectively mitigating mutual interference between sensing and communication. The proposed methods significantly enhance tag interrogation range and identification success rate while reducing overall system transmit power.

Technology Category

• Search and Optimization: Mixed Discrete/Continuous Search
• Planning, Routing, and Scheduling: Optimization of Spatio-temporal Systems
• Constraint Satisfaction and Optimization: Distributed CSP/Optimization

Application Category

• Systems and Infrastructure for Web, Mobile and WoT: Energy management for devices in mobile Web and WoT environments
• Security and Privacy: Large-scale security measurements
• Search and Retrieval-Augmented AI: Vertical and domain-specific search

Abstract

This paper explores an integrated sensing and communication (ISAC) system with backscattering RFID tags. In this setup, an access point employs communication beams to serve communication users while leveraging a sensing beam to interrogate RFID tags. Under the total transmit power constraint of the system, our objective is to design a joint sensing and communication beamforming codebook by considering the tag interrogation and communication requirements. To lay a foundation for the codebook design problem, we first study the beamforming design problem in a single-tag scenario and investigate two approaches: (i) a zero-forcing approach with optimized sensing/communication power allocation, for which a closed-form solution is derived under a dominant sensitivity condition, and (ii) a joint sensing and communication beamforming design obtained by transmit power minimization. Then, we investigate the codebook design problem in a multi-tag scenario. To resolve this, we propose a sector-based joint sensing and communication beamforming codebook that scans the region of interest. For each sector, semidefinite relaxation and generalized Benders decomposition are employed to handle the resulting optimization. The simulation results show that the proposed joint beamforming designs can effectively mitigate the mutual interference between sensing and communication functionalities, thus enhancing the interrogation range of the tags with minimized transmit power. Also, the efficacy of the proposed sector-based codebook design has been demonstrated in terms of interrogation success rate, offering a promising approach for the ISAC-backscattering systems.

Problem

• Integrated Sensing and Communication
• Backscattering RFID
• Beamforming
• Codebook Design
• Mutual Interference

Innovation

• Integrated Sensing and Communication (ISAC)
• Backscattering RFID
• Joint Beamforming
• Codebook Design
• Semidefinite Relaxation