Optimal Spatial Signal Design for mmWave Positioning under Imperfect Synchronization

TL;DR

This paper develops an optimal and robust spatial signal design for mmWave positioning that accounts for imperfect synchronization, demonstrating improved accuracy over traditional methods through numerical analysis.

Contribution

It introduces a novel robust design and a codebook-based heuristic for mmWave positioning under synchronization uncertainties, enhancing performance and reducing complexity.

Findings

Proposed designs outperform conventional directional beam codebooks.

Achieve near-optimal position-error-bound (PEB) performance.

Effective for both analog and digital architectures.

Abstract

We consider the problem of spatial signal design for multipath-assisted mmWave positioning under limited prior knowledge on the user's location and clock bias. We propose an optimal robust design and, based on the low-dimensional precoder structure under perfect prior knowledge, a codebook-based heuristic design with optimized beam power allocation. Through numerical results, we characterize different position-error-bound (PEB) regimes with respect to clock bias uncertainty and show that the proposed low-complexity codebook-based designs outperform the conventional directional beam codebook and achieve near-optimal PEB performance for both analog and digital architectures.