Title
The generalized triangular decomposition
Abstract
Given a complex matrix H, we consider the decomposition H = QRP*, where R is upper triangular and Q and P have orthonormal columns. Special instances of this decomposition include the singular value decomposition (SVD) and the Schur decomposition where R is an upper triangular matrix with the eigenvalues of H on the diagonal. We show that any diagonal for R can be achieved that satisfies Weyl's multiplicative majorization conditions: (k)Pi(i =1) |r(i)| <= (k)Pi(i =1) sigma(i), 1 <= k < K, (k)Pi(i =1) |r(i)| = (k)Pi(i =1) sigma(i), where K is the rank of H, sigma(i) is the i-th largest singular value of H, and r(i) is the i-th largest (in magnitude) diagonal element of R. Given a vector r which satisfies Weyl's conditions, we call the decomposition H = QRP*, where R is upper triangular with prescribed diagonal r, the generalized triangular decomposition (GTD). A direct (nonrecursive) algorithm is developed for computing the GTD. This algorithm starts with the SVD and applies a series of permutations and Givens rotations to obtain the GTD. The numerical stability of the GTD update step is established. The GTD can be used to optimize the power utilization of a communication channel, while taking into account quality of service requirements for subchannels. Another application of the GTD is to inverse eigenvalue problems where the goal is to construct matrices with prescribed eigenvalues and singular values.
Year
DOI
Venue
2008
10.1090/S0025-5718-07-02014-5
MATHEMATICS OF COMPUTATION
Keywords
Field
DocType
generalized triangular decomposition,geometric mean decomposition,matrix factorization,unitary factorization,singular value decomposition,Schur decomposition,MIMO systems,inverse eigenvalue problems
Diagonal,Singular value decomposition,Combinatorics,Singular value,Matrix (mathematics),Matrix decomposition,Schur decomposition,Triangular matrix,Eigenvalues and eigenvectors,Mathematics
Journal
Volume
Issue
ISSN
77
262
0025-5718
Citations 
PageRank 
References 
18
1.02
9
Authors
3
Name
Order
Citations
PageRank
Yi Jiang16513.28
William W. Hager21603214.67
Jian Li3141479.27