Engineering Commons^™

Soft-Decision Equalization Techniques For Frequency Selective Mimo Channels, Shoumin Liu

Dissertations, Master's Theses and Master's Reports - Open

Multi-input multi-output (MIMO) technology is an emerging solution for high data rate wireless communications. We develop soft-decision based equalization techniques for frequency selective MIMO channels in the quest for low-complexity equalizers with BER performance competitive to that of ML sequence detection.

We first propose soft decision equalization (SDE), and demonstrate that decision feedback equalization (DFE) based on soft-decisions, expressed via the posterior probabilities associated with feedback symbols, is able to outperform hard-decision DFE, with a low computational cost that is polynomial in the number of symbols to be recovered, and linear in the signal constellation size. Building upon the probabilistic …

Control Algorithms For Large Scale Adaptive Optics, Piotr Piatrou

Dissertations, Master's Theses and Master's Reports - Open

In this dissertation, the problem of creating effective large scale Adaptive Optics (AO) systems control algorithms for the new generation of giant optical telescopes is addressed. The effectiveness of AO control algorithms is evaluated in several respects, such as computational complexity, compensation error rejection and robustness, i.e. reasonable insensitivity to the system imperfections. The results of this research are summarized as follows:

1. Robustness study of Sparse Minimum Variance Pseudo Open Loop Controller (POLC) for multi-conjugate adaptive optics (MCAO). The AO system model that accounts for various system errors has been developed and applied to check the stability and performance …

Reconstruction Of Anisoplanatic Adaptive Optics Images, Mathieu Aubailly

Dissertations, Master's Theses and Master's Reports - Open

No abstract provided.