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arXiv · 1508.00256

Volume of Metric Balls in High-Dimensional Complex Grassmann Manifolds

Renaud-Alexandre Pitaval·Lu Wei·Olav Tirkkonen·Jukka Corander
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Abstract

Volume of metric balls relates to rate-distortion theory and packing bounds on codes. In this paper, the volume of balls in complex Grassmann manifolds is evaluated for an arbitrary radius. The ball is defined as a set of hyperplanes of a fixed dimension with reference to a center of possibly different dimension, and a generalized chordal distance for unequal dimensional subspaces is used. First, the volume is reduced to one-dimensional integral representation. The overall problem boils down to evaluating a determinant of a matrix of the same size as the subspace dimensionality. Interpreting this determinant as a characteristic function of the Jacobi ensemble, an asymptotic analysis is carried out. The obtained asymptotic volume is moreover refined using moment-matching techniques to provide a tighter approximation in finite-size regimes. Lastly, the pertinence of the derived results is shown by rate-distortion analysis of source coding on Grassmann manifolds.

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Renaud-Alexandre Pitaval, Lu Wei, Olav Tirkkonen, Jukka Corander. 2015-08-02. Volume of Metric Balls in High-Dimensional Complex Grassmann Manifolds. https://arxiv.org/abs/1508.00256

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