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Type of Document	Dissertation
Author	Fleming, Michael
Author's Email Address	mike AT z.caltech.edu
URN	etd-05282004-170744
Persistent URL	http://resolver.caltech.edu/CaltechETD:etd-05282004-170744
Title	On source coding for networks
Degree	PhD
Option	Electrical Engineering
Advisory Committee	Advisor Name Title Michelle Effros Committee Chair Babak Hassibi Committee Member Jehoshua Bruck Committee Member Robert McEliece Committee Member Steven Low Committee Member
Keywords	side information broadcast feedback multiterminal multiple access vector quantization
Date of Defense	2004-05-10
Availability	unrestricted
Abstract In this thesis, I examine both applied and theoretical issues in network source coding. The applied results focus on the construction of locally rate-distortion-optimal vector quantizers for networks. I extend an existing vector quantizer design algorithm for arbitrary network topologies [1] to allow for the use of side information at the decoder and for the presence of channel errors. I show how to implement the algorithm and use it to design codes for several different systems. The implementation treats both fixed-rate and variable-rate quantizer design and includes a discussion of convergence and complexity. Experimental results for several different systems demonstrate in practice some of the potential performance benefits (in terms of rate, distortion, and functionality) of incorporating a network's topology into the design of its data compression system. The theoretical work covers several topics. Firstly, for a system with some side information known at both the encoder and the decoder, and some known only at the decoder, I derive the rate-distortion function and evaluate it for binary symmetric and Gaussian sources. I then apply the results for binary sources in evaluating the binary symmetric rate-distortion function for a system where the presence of side information at the decoder is unreliable. Previously, only upper and lower bounds were known for that problem. Secondly, I address with an example the question of whether feedback from a decoder to an encoder ever enlarges the achievable rate region for lossless network source coding of memoryless sources. Thirdly, I show how cutset methods can yield quick and simple rate-distortion converses for any source coding network. Finally, I present rate-distortion results for two different broadcast source coding systems.
Files	Filename       Size       Approximate Download Time (Hours:Minutes:Seconds)     28.8 Modem   56K Modem   ISDN (64 Kb)   ISDN (128 Kb)   Higher-speed Access    thesis.pdf 1.02 Mb 00:04:44 00:02:26 00:02:08 00:01:04 00:00:05