Dual-Pilot Channel Estimation and Interference-Aware Beamforming for Monostatic MIMO Backscatter Systems under Jamming Attacks

Abstract

Accurate estimation of backscatter channels is crucial for enabling effective beamforming in multi-antenna readers. While full-duplex architectures improve the range of monostatic Backscatter Communication (BSC) systems, they remain highly vulnerable to jamming, which degrades channel estimation (CE) and transceiver performance. We propose a dual-pilot CE protocol for monostatic BSC systems under jamming, which exploits tag spread-spectrum sequences to suppress direct-link interference and leverages reader pilots to estimate and mitigate cascaded jamming components. The method relies on the quasi-static statistical structure of the jammer rather than instantaneous waveform cancellation, enabling robust channel recovery. Using the estimated channel state information, we design interferenceaware precoders and combiners at the reader to improve resilience against jamming. Simulations show that the proposed framework significantly enhances CE accuracy and resilience, providing key insights into secure transceiver design for BSC systems.