Cramér-Rao Bounds for Near-Field Sensing: A Generic Modular Architecture

• Published in: IEEE wireless communications letters Vol. 13; no. 8; pp. 2205 - 2209
• Main Authors: Meng, Chunwei, Ma, Dingyou, Chen, Xu, Feng, Zhiyong, Liu, Yuanwei
• Format: Journal Article
• Language: English
• Published: Piscataway IEEE 01.08.2024; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Antenna arrays; Antennas; Apertures; Arrays; Closed form solutions; Computer architecture; Cramer-Rao bounds; Cramér-Rao bounds; Exact solutions; Far fields; generic modular array; Layouts; Modular systems; Near fields; near-field sensing; Pulse width modulation; Sensors; Spherical waves; Vectors
• ISSN: 2162-2337; 2162-2345
• DOI: 10.1109/LWC.2024.3406577

A generic modular array architecture is proposed, featuring uniform/non-uniform subarray layouts that allows for flexible deployment. The bistatic near-field sensing system is considered, where the target is located in the near-field of the whole modular array and the far-field of each subarray. Then, the closed-form expressions of Cramér-Rao bounds (CRBs) for range and angle estimations are derived based on the hybrid spherical and planar wave model (HSPM). Simulation results validate the accuracy of the derived closed-form CRBs and demonstrate that: i) The HSPM with varying angles of arrival (AoAs) between subarrays can reduce the CRB for range estimation compared to the traditional HSPM with shared AoA; and ii) The proposed generic modular architecture with subarrays positioned closer to the edges can significantly reduce the CRBs compared to the traditional modular architecture with uniform subarray layout, when the array aperture is fixed.