Clutter-Aware Integrated Sensing and Communication: Models, Methods, and Future Directions

TL;DR

This paper develops a comprehensive model for clutter in wideband MIMO-OFDM ISAC systems, reviews suppression techniques, and discusses proactive clutter-aware transceiver design for robust sensing and communication.

Contribution

It introduces a unified clutter model for wideband MIMO-OFDM ISAC, reviews existing suppression methods, and proposes clutter-aware transceiver co-design strategies.

Findings

Unified wideband MIMO-OFDM clutter model developed

Review of clutter suppression techniques in various domains

Discussion of proactive clutter-aware transceiver design

Abstract

Integrated sensing and communication (ISAC) can substantially improve spectral, hardware, and energy efficiency by unifying radar sensing and data communications. In wideband and scattering-rich environments, clutter often dominates weak target reflections and becomes a fundamental bottleneck for reliable sensing. Practical ISAC clutter includes "cold" clutter arising from environmental backscatter of the probing waveform, and "hot" clutter induced by external interference and reflections from the environment whose statistics can vary rapidly over time. In this article, we develop a unified wideband multiple-input multiple-output orthogonal frequency-division multiplexing (MIMO-OFDM) signal model that captures both clutter types across the space, time, and frequency domains. Building on this model, we review clutter characterization at multiple levels, including amplitude statistics, robust spherically invariant random vector (SIRV) modeling, and structured covariance representations suitable for limited-snapshot regimes. We then summarize receiver-side suppression methods in the temporal and spatial domains, together with extensions to space-time adaptive processing (STAP) and space-frequency-time adaptive processing (SFTAP), and we provide guidance on selecting techniques under different waveform and interference conditions. To move beyond reactive suppression, we discuss clutter-aware transceiver co-design that couples beamforming and waveform optimization with practical communication quality-of-service (QoS) constraints to enable proactive clutter avoidance. We conclude with open challenges and research directions toward environment-adaptive and clutter-resilient ISAC for next-generation networks.