Wideband Sensing with Dynamic Metasurface Antennas under Realistic Phase Response Modeling

TL;DR

This paper analyzes how realistic features of Dynamic Metasurface Antennas affect wideband sensing performance, revealing that frequency selectivity and waveguide effects degrade estimation accuracy, validated through numerical results.

Contribution

It introduces a practical DMA response model and derives Fisher Information and Cramer-Rao bounds for localization and scattering point sensing.

Findings

Frequency selectivity reduces effective bandwidth.

Waveguide effects decrease coherent gain and aperture.

Estimation errors increase due to practical DMA features.

Abstract

This paper investigates the impact of practical features of the emerging antenna array technology of Dynamic Metasurface Antennas (DMAs) when used for wideband sensing. By adopting a realistic DMA response model capturing frequency selective magnetic polarizability, finite resonant frequency tuning, and waveguide phase and leakage effects, we first present a compact observation model for user localization and multiple scattering points sensing through DMA-based analog combining of Orthogonal Frequency Division Multiplexing (OFDM) pilots transmitted in the uplink direction. Building on this model, we derive the Fisher Information Matrix (FIM), the equivalent FIM, and the corresponding Cramer-Rao Bounds (CRBs) for the relevant spatitemporal parameters estimation. The analysis reveals that frequency selectivity reduces the effective information bandwidth and distorts the DMA-based reception manifold, while waveguide attenuation decreases both the coherent combining gain and the effective aperture, thereby degrading estimation accuracy. Numerical results validate the analysis and confirm the resulting inflation in the delay, angle, and position error bounds.