Nested quantization and Slepian-Wolf coding: a Wyner-Ziv coding paradigm for i.i.d. sources

A new paradigm for Wyner-Ziv coding of i.i.d. sources is proposed that consists of nested quantization and Slepian-Wolf coding. The former plays the role of quantization with side information (at the decoder) and the latter lossless coding with side information. The proposed Slepian-Wolf coded nested quantization (SWC-NQ) framework generalizes the classic source coding approach of quantization and lossless/entropy coding. The main thrust is to treat Wyner-Ziv coding as a source-channel coding problem in which the side information is taken into account in the channel coding component via binning. For Gaussian sources with MSE measure, assuming nested lattice quantization with ideal Slepian-Wolf coding and high rate, we establish system performance bounds of SWC-NQ similar to those in classic source coding, showing that 1-D/2-D nested lattice quantization performs 1.53/1.36 dB worse than the Wyner-Ziv distortion-rate function D_WZ{R). Using nested lattices in higher dimensions or nested trellis-coded quantization (TCQ) could possibly approach D_WZ(R) even further. We implement 1-D and 2-D nested lattice quantization, together with irregular low-density parity-check (LDPC) codes for Slepian-Wolf coding, obtaining performance close to the corresponding theoretical limits.