Abstract
We estimate n phases (angles) from noisy pairwise relative phase measurements. The task is modeled as a nonconvex least-squares optimization problem. It was recently shown that this problem can be solved in polynomial time via convex relaxation, under some conditions on the noise. In this paper, under similar but more restrictive conditions, we show that a modified version of the power method converges to the global optimum. This is simpler and (empirically) faster than convex approaches. Empirically, they both succeed in the same regime. Further analysis shows that, in the same noise regime as previously studied, second-order necessary optimality conditions for this quadratically constrained quadratic program are also sufficient, despite nonconvexity.
Original language | English (US) |
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Pages (from-to) | 2355-2377 |
Number of pages | 23 |
Journal | SIAM Journal on Optimization |
Volume | 26 |
Issue number | 4 |
DOIs | |
State | Published - 2016 |
All Science Journal Classification (ASJC) codes
- Software
- Theoretical Computer Science
Keywords
- Angular synchronization
- Generalized power method
- Nonconvex optimization
- Optimization on manifolds
- Projected power method
- Quadratically constrained quadratic pro- gramming
- Sufficient optimality conditions