Hardware Distortion Aware Precoding for ISAC Systems

TL;DR

This paper investigates how hardware impairments affect sensing in ISAC systems and proposes distortion-aware precoding methods to enhance sensing robustness amidst clutter and hardware distortions.

Contribution

It introduces a novel distortion- and clutter-aware precoding strategy and an alternative power allocation method for improved sensing in hardware-impaired ISAC systems.

Findings

Hardware distortions significantly degrade sensing performance.

Proposed precoding improves sensing robustness in cluttered environments.

Numerical results show substantial gains over distortion-unaware designs.

Abstract

The impact of hardware impairments on the spectral efficiency of communication systems is well studied, but their effect on sensing performance remains unexplored. In this paper, we analyze the influence of hardware impairments on integrated sensing and communication (ISAC) systems in cluttered environments. We derive the sensing signal-to-clutter-plus-noise ratio (SCNR) and show that hardware distortions significantly degrade sensing performance by enhancing clutter-induced noise, which masks target echoes. The isotropic nature of transmit distortion due to multiple stream transmission further complicates clutter suppression. To address this, we propose a distortion- and clutter-aware precoding strategy that minimizes the deviation from the communication-optimized precoder while improving sensing robustness. We also propose an alternative power allocation-based approach that reduces computational complexity. Numerical results confirm the effectiveness of the proposed approaches in overcoming hardware- and clutter-induced limitations, demonstrating significant performance gains over distortion-unaware designs.