Driven by a host of emerging applications (e.g., sensor networks and wireless video),
distributed source coding (i.e., Slepian-Wolf coding, Wyner-Ziv coding and various other
forms of multiterminal source coding), has recently become a very active research area.
This dissertation focuses on multiterminal (MT) source coding problem, and consists
of three parts. The first part studies the sum-rate loss of an important special case
of quadratic Gaussian multi-terminal source coding, where all sources are positively symmetric
and all target distortions are equal. We first give the minimum sum-rate for joint
encoding of Gaussian sources in the symmetric case, and then show that the supremum of
the sum-rate loss due to distributed encoding in this case is 1
2 log2
5
4 = 0:161 b/s when L = 2
and increases in the order of
ยบ
L
2 log2 e b/s as the number of terminals L goes to infinity.
The supremum sum-rate loss of 0:161 b/s in the symmetric case equals to that in general
quadratic Gaussian two-terminal source coding without the symmetric assumption. It is
conjectured that this equality holds for any number of terminals.
In the second part, we present two practical MT coding schemes under the framework
of Slepian-Wolf coded quantization (SWCQ) for both direct and indirect MT problems.
The first, asymmetric SWCQ scheme relies on quantization and Wyner-Ziv coding, and it
is implemented via source splitting to achieve any point on the sum-rate bound. In the second,
conceptually simpler scheme, symmetric SWCQ, the two quantized sources are compressed
using symmetric Slepian-Wolf coding via a channel code partitioning technique that is capable of achieving any point on the Slepian-Wolf sum-rate bound. Our practical
designs employ trellis-coded quantization and turbo/LDPC codes for both asymmetric and
symmetric Slepian-Wolf coding. Simulation results show a gap of only 0.139-0.194 bit per
sample away from the sum-rate bound for both direct and indirect MT coding problems.
The third part applies the above two MT coding schemes to two practical sources, i.e.,
stereo video sequences to save the sum rate over independent coding of both sequences.
Experiments with both schemes on stereo video sequences using H.264, LDPC codes for
Slepian-Wolf coding of the motion vectors, and scalar quantization in conjunction with
LDPC codes for Wyner-Ziv coding of the residual coefficients give slightly smaller sum
rate than separate H.264 coding of both sequences at the same video quality.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/ETD-TAMU-2344 |
| Date | 15 May 2009 |
| Creators | Yang, Yang |
| Contributors | Xiong, Zixiang |
| Source Sets | Texas A and M University |
| Language | en_US |
| Detected Language | English |
| Type | Book, Thesis, Electronic Dissertation, text |
| Format | electronic, application/pdf, born digital |
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