Transmission of vector quantization over a frequency-selective Rayleigh fading CDMA channel
Date
2005-12-08
Authors
Journal Title
Journal ISSN
Volume Title
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ORCID
Type
Degree Level
Masters
Abstract
Recently, the transmission of vector quantization (VQ) over a code-division multiple access (CDMA) channel has received a considerable attention in research community. The complexity of the optimal decoding for VQ in CDMA communications is prohibitive for implementation, especially for systems with a medium or large number of users. A suboptimal approach to VQ decoding over a CDMA channel, disturbed by additive white Gaussian noise (AWGN), was recently developed. Such a suboptimal decoder is built from a soft-output multiuser detector (MUD), a soft bit estimator and the optimal soft VQ decoders of individual users. Due to its lower complexity and good performance, such a decoding scheme is an attractive alternative to the complicated optimal decoder. It is necessary to extend this decoding scheme for a frequency-selective Rayleigh fading CDMA channel, a channel model typically seen in mobile wireless communications. This is precisely the objective of this thesis. Furthermore, the suboptimal decoders are obtained not only for binary phase shift keying (BPSK), but also for M-ary pulse amplitude modulation (M-PAM). This extension offers a flexible trade-off between spectrum efficiency and performance of the systems. In addition, two algorithms based on distance measure and reliability processing are
introduced as other alternatives to the suboptimal decoder. Simulation results indicate that the suboptimal decoders studied in this thesis also performs very well over a frequency-selective Rayleigh fading CDMA channel.
Description
Keywords
code-division multiple access, combined source and channel coding, vector quantization, frequency-selective fading channel, multiuser detection
Citation
Degree
Master of Science (M.Sc.)
Department
Electrical Engineering
Program
Electrical Engineering