Simultaneous Beamforming and Anti-Jamming With Intelligent Omni-Surfaces

TL;DR

This paper proposes a joint beamforming and intelligent omni-surface design to nullify jamming and enhance desired signals in wireless systems, addressing challenges of coupled phase shifts and imperfect information.

Contribution

It introduces a coupling-aware optimization algorithm for IOS phase shifts and beamforming, improving anti-jamming performance in multi-user wireless systems.

Findings

Significant sum rate improvement under jamming attacks

Effective handling of coupled and discrete IOS phase shifts

Robust performance with imperfect jammer-related channel information

Abstract

Wireless transmission is vulnerable to malicious jamming attacks due to the openness of wireless channels, posing a severe threat to wireless communications. Current anti-jamming studies primarily focus on either enhancing desired signals or mitigating jamming, resulting in limited performance. To address this issue, intelligent omni-surface (IOS) is a promising solution. By jointly designing its reflective and refractive properties, the IOS can simultaneously nullify jamming and enhance desired signals. In this paper, we consider an IOS-aided multi-user anti-jamming communication system, aiming to improve desired signals and nullify jamming by optimizing IOS phase shifts and transmit beamforming. However, this is challenging due to the coupled and discrete IOS reflection and refraction phase shifts, the unknown jammer's beamformer, and imperfect jammer-related channel state information. To tackle this, we relax IOS phase shifts to continuous states and optimize with a coupling-aware algorithm using the Cauchy-Schwarz inequality and S-procedure, followed by a local search to recover discrete states. Simulation results show that the proposed scheme significantly improves the sum rate amid jamming attacks.