The Mathematical Institute, University of Oxford, Eprints Archive

On Block Coherence of Frames

Calderbank, Robert and Thompson, Andrew and Xie, Yao (2015) On Block Coherence of Frames. Technical Report. Unspecified. (Submitted)



Block coherence of matrices plays an important role in analyzing the performance of block compressed sensing recovery algorithms (Bajwa and Mixon, 2012). In this paper, we characterize two block coherence metrics: worstcase and average block coherence. First, we present lower bounds on worst-case block coherence, in both the general case and also when the matrix is constrained to be a union of orthobases. We then present deterministic matrix constructions based upon Kronecker products which obtain these lower bounds. We also characterize the worstcase block coherence of random subspaces. Finally, we present a flipping algorithm that can improve the average block coherence of a matrix, while maintaining the worst-case block coherence of the original matrix. We provide numerical examples which demonstrate that our proposed deterministic matrix construction performs well in block compressed sensing.

Item Type:Technical Report (Technical Report)
Subjects:H - N > Numerical analysis
Research Groups:Numerical Analysis Group
ID Code:1885
Deposited By: Helen Taylor
Deposited On:27 May 2015 08:13
Last Modified:29 May 2015 19:35

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