Fundamental Limits for Wide-Band Near-Field Sensing
Analysis
This paper investigates the fundamental limits of wide-band near-field sensing using extremely large-scale antenna arrays (ELAAs), crucial for 6G systems. It provides Cramér-Rao bounds (CRBs) for joint estimation of target parameters (position, velocity, radar cross-section) in a wide-band setting, considering frequency-dependent propagation and spherical-wave geometry. The work is significant because it addresses the challenges of wide-band operation where delay, Doppler, and spatial effects are tightly coupled, offering insights into the roles of bandwidth, coherent integration length, and array aperture. The derived CRBs and approximations are validated through simulations, providing valuable design-level guidance for future 6G systems.
Key Takeaways
“The paper derives fundamental estimation limits for a wide-band near-field sensing systems employing orthogonal frequency-division multiplexing signaling over a coherent processing interval.”