A rounding error analysis is presented for a divide-and-conquer algorithm to solve linear systems with block Hessenberg matrices. Conditions are derived under which the algorithm computes a stable solution. The algorithm is shown to be stable for block diagonally dominant matrices and for M-matrices.

Supported by the Graduiertenkolleg \Analyse und Konstruktion in der Mathematik".

Modeling semantics based on dataflow graphs are used widely in design tools for digital signal processing (DSP). This paper develops efficient techniques for representing and manipulating blockbased operations in dataflow-based DSP design tools. In this context, a block refers to a finite-length sequence of data items, such as a sequence of speech samples, an image, or a group of video frames, ...

A method is presented for designing lossless sliding block compression schemes that map constrained sequences onto unconstrained ones The new compression scheme is incorporated into a coding technique for noisy constrained channels which has appli cations to magnetic and optical storage As suggested recently by Immink the use of a lossless compression code can improve the performance of a modi ...

This paper presents a systematic theoretical and numerical evaluation of three common block preconditioners in a Krylov subspace method for solving symmetric indefinite linear systems. The focus is on large-scale real world problems where block approximations are a practical necessity. The main illustration is the performance of the block diagonal, constrained, and lower triangular precondition...

In this paper, we propose a multilayered spacefrequency block coded OFDM system, which is a combination of the vertical layered space-time architecture, known as V-BLAST, and the space-frequency block coded OFDM system. This system is designed to provide reliable as well as very high data rate communications over frequency-selective fading channels with low decoding complexity. Orthogonal Frequ...