2026-09-19T04:52:09Z https://www.ideals.illinois.edu/oai-pmh

oai:www.ideals.illinois.edu:2142/80700 2023-07-11 col_2142_5131 col_2142_8888 com_2142_5130 com_2142_8887 com_2142_234

Upamanyu Madhow Visotsky, Eugene 2015-09-25T20:07:40Z 2015-09-25T20:07:40Z 10000-01-01 2000 2000 The first topic considered in the thesis is interference suppression using space-time transmit filters for a multiuser system, assuming perfect channel feedback. The filter design is formulated as an optimization problem, and an iterative algorithm that converges to the global optimum is derived. Next, the effect of imperfections in the channel feedback is investigated, focusing on a single receiver. Conditioned on the feedback, the space-time channel estimate at the transmitter is modeled as a random vector with a complex Gaussian distribution, which is consistent with standard models of Rayleigh and Rician fading channels. Optimum strategies that maximize the long term information transfer rate are derived under a variety of assumptions regarding this distribution. It is shown that the simple strategy of beamforming is close to optimal in many situations of interest. Finally, methods for the generation of channel feedback are devised. These methods employ Wiener filtering at the transmitter and the receiver for channel estimation and prediction from information derived from the pilot and feedback, respectively. Furthermore, these schemes employ the novel approach of directly sending analogue values back to the transmitter, thus avoiding quantization error. The new schemes are shown to provide better channel estimates than quantization-based feedback schemes currently being standardized for third generation cellular systems. Made available in DSpace on 2015-09-25T20:07:40Z (GMT). No. of bitstreams: 2 license.txt: 4848 bytes, checksum: 96035ab3f5e1c23cc7138a224ce498bd (MD5) 3017008.pdf: 4007398 bytes, checksum: 6c68215be0cf477ff27b8c6db9912613 (MD5) Previous issue date: 2000 Embargo set by: Seth Robbins for item 81982 Lift date: Forever Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs U of I Only 78 p. Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2000. http://hdl.handle.net/2142/80700 (MiAaPQ)AAI3017008 eng Engineering, Electronics and Electrical Space -Time Transmit Precoding and Interference Suppression for a Wireless Downlink text Electrical Engineering Electrical Engineering University of Illinois at Urbana-Champaign Dissertation Ph.D.