A Rotation Method for Computing the QR-Decomposition
Franklin T. Luk · SIAM Journal on Scientific and Statistical Computing · 1986
A parallel method for computing the QR-decomposition of an $n \times n$ matrix is proposed. It requires $O(n^2 )$ processors and $O(n)$ units of time. The method can be extended to handle an $m \times n$ matrix $(m \geqq n)$. The requirements then become $O(n^2 )$ processors and $O(m)$ time.