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theses

A combined source-channel coding and modulation approach is implemented for the encoding, transmission and remote reconstruction of a first-order one-dimensional Gauss-Markov source described by the correlation coefficient ρ. The source encoder employs differential pulse code modulation (DPCM). This is an efficient encoding scheme in the absence of channel errors. However, DPCM degrades rapidly in the presence of channel errors. Trellis-Coded Modulation is used to provide error protection without incurring a bandwidth expansion. This is accomplished by using m-bit DPCM with a rate m/(m + 1) trellis code and a 2m+1-ary modulation technique such as multiple phase-shift keying (MPSK) or quadrature amplitude modulation (QAM). The trellis codes used are those developed by Ungerboeck. Performance of the overall system is evaluated on a mean square reconstructed error (MSRE) versus channel signal-to-noise ratio (SNRin) criterion for an AWGN Channel. The system performance is increased by 3 to 7 dB as compared to an uncoded system and results are within 1.0 to 2.3 dB of the R0 bound. The technique demonstrates an effective bandwidth efficient means for transmitting source encoded date represented by more than one bit per source symbol which has not been previously demonstrated in the technical literature.

M.S.

Includes bibliographical references (p. 132-135)

by Andrew Todd Weitzner

doi:10.7282/T3639RW5

ETD graduate

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