Title
Information Theoretic Limits for Phase Retrieval With Subsampled Haar Sensing Matrices
Abstract
We study information theoretic limits of recovering an unknown n dimensional, complex signal vector x <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">*</sub> with unit norm from m magnitude-only measurements of the form y <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">i</sub> = |(Ax <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">*</sub> ) <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">i</sub> | <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> , i = 1, 2 ..., m, where A is the sensing matrix. This is known as the Phase Retrieval problem and models practical imaging systems where measuring the phase of the observations is difficult. Since in a number of applications, the sensing matrix has orthogonal columns, we model the sensing matrix as a subsampled Haar matrix formed by picking n columns of a uniformly random m X m unitary matrix. We study this problem in the high dimensional asymptotic regime, where m, n → ∞, while m/n → δ with δ being a fixed number, and show that if m <; (2 - o <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">n</sub> (1)) · n, then any estimator is asymptotically orthogonal to the true signal vector x <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">*</sub> . This lower bound is sharp since when m > (2 + o <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">n</sub> (1)) · n, estimators that achieve a non trivial asymptotic correlation with the signal vector are known from previous works.
Year
DOI
Venue
2020
10.1109/TIT.2020.3015173
IEEE Transactions on Information Theory
Keywords
DocType
Volume
Phase retrieval,random orthogonal matrices,subsampled Haar matrices,coded diffraction pattern,large deviation theory,random matrix theory,phase transition,weak recovery threshold
Journal
66
Issue
ISSN
Citations 
12
0018-9448
1
PageRank 
References 
Authors
0.35
0
3
Name
Order
Citations
PageRank
Dudeja Rishabh110.35
Junjie Ma214815.24
Arian Maleki380357.52