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Thu Jun 13 04:35 PM -- 04:40 PM (PDT) @ Seaside Ballroom
Multi-Frequency Phase Synchronization
Tingran Gao · Zhizhen Zhao

We propose a novel formulation for phase synchronization---the statistical problem of jointly estimating alignment angles from noisy pairwise comparisons---as a nonconvex optimization problem that enforces consistency among the pairwise comparisons in multiple frequency channels. Inspired by harmonic retrieval in signal processing, we develop a simple yet efficient two-stage algorithm that leverages the multi-frequency information. We demonstrate in theory and practice that the proposed algorithm significantly outperforms state-of-the-art phase synchronization algorithms, at a mild computational costs incurred by using the extra frequency channels. We also extend our algorithmic framework to general synchronization problems over compact Lie groups.