Yang, Yang (2004-08). Wyner-Ziv coding based on TCQ and LDPC codes and extensions to multiterminal source coding. Master's Thesis. Thesis uri icon

abstract

  • 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. In this thesis, we first design a practical coding scheme for the quadratic Gaussian Wyner-Ziv problem, because in this special case, no rate loss is suffered due to the unavailability of the side information at the encoder. In order to approach the Wyner-Ziv distortion limit D??W Z(R), the trellis coded quantization (TCQ) technique is employed to quantize the source X, and irregular LDPC code is used to implement Slepian-Wolf coding of the quantized source input Q(X) given the side information Y at the decoder. An optimal non-linear estimator is devised at the joint decoder to compute the conditional mean of the source X given the dequantized version of Q(X) and the side information Y . Assuming ideal Slepian-Wolf coding, our scheme performs only 0.2 dB away from the Wyner-Ziv limit D??W Z(R) at high rate, which mirrors the performance of entropy-coded TCQ in classic source coding. Practical designs perform 0.83 dB away from D??W Z(R) at medium rates. With 2-D trellis-coded vector quantization, the performance gap to D??W Z(R) is only 0.66 dB at 1.0 b/s and 0.47 dB at 3.3 b/s. We then extend the proposed Wyner-Ziv coding scheme to the quadratic Gaussian multiterminal source coding problem with two encoders. Both direct and indirect settings of multiterminal source coding are considered. An asymmetric code design containing one classical source coding component and one Wyner-Ziv coding component is first introduced and shown to be able to approach the corner points on the theoretically achievable limits in both settings. To approach any point on the theoretically achievable limits, a second approach based on source splitting is then described. One classical source coding component, two Wyner-Ziv coding components, and a linear estimator are employed in this design. Proofs are provided to show the achievability of any point on the theoretical limits in both settings by assuming that both the source coding and the Wyner-Ziv coding components are optimal. The performance of practical schemes is only 0.15 b/s away from the theoretical limits for the asymmetric approach, and up to 0.30 b/s away from the limits for the source splitting approach.
  • 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.
    In this thesis, we first design a practical coding scheme for the quadratic Gaussian
    Wyner-Ziv problem, because in this special case, no rate loss is suffered due to
    the unavailability of the side information at the encoder. In order to approach the
    Wyner-Ziv distortion limit D??W Z(R), the trellis coded quantization (TCQ) technique
    is employed to quantize the source X, and irregular LDPC code is used to implement
    Slepian-Wolf coding of the quantized source input Q(X) given the side information
    Y at the decoder. An optimal non-linear estimator is devised at the joint decoder
    to compute the conditional mean of the source X given the dequantized version of
    Q(X) and the side information Y . Assuming ideal Slepian-Wolf coding, our scheme
    performs only 0.2 dB away from the Wyner-Ziv limit D??W Z(R) at high rate, which
    mirrors the performance of entropy-coded TCQ in classic source coding. Practical
    designs perform 0.83 dB away from D??W Z(R) at medium rates. With 2-D trellis-coded
    vector quantization, the performance gap to D??W Z(R) is only 0.66 dB at 1.0 b/s and
    0.47 dB at 3.3 b/s.
    We then extend the proposed Wyner-Ziv coding scheme to the quadratic Gaussian
    multiterminal source coding problem with two encoders. Both direct and indirect
    settings of multiterminal source coding are considered. An asymmetric code design
    containing one classical source coding component and one Wyner-Ziv coding component
    is first introduced and shown to be able to approach the corner points on the
    theoretically achievable limits in both settings. To approach any point on the theoretically
    achievable limits, a second approach based on source splitting is then described.
    One classical source coding component, two Wyner-Ziv coding components, and a
    linear estimator are employed in this design. Proofs are provided to show the achievability
    of any point on the theoretical limits in both settings by assuming that both
    the source coding and the Wyner-Ziv coding components are optimal. The performance
    of practical schemes is only 0.15 b/s away from the theoretical limits for the
    asymmetric approach, and up to 0.30 b/s away from the limits for the source splitting
    approach.

publication date

  • August 2004