Practical codes for lossy compression when side information may be absent

Practical codes are developed for quadratic Gaussian lossy compression when side information may be absent by hybridizing successively refinable trellis coded quantization (SR-TCQ) and low-density parity-check (LDPC) codes. A 2-refinement level SR-TCQ is used to generate a common description for both decoders and an individual description for the decoder with side information. Then, the common description is losslessly compressed while the individual description is compressed using a LDPC code which exploits the side information in a belief propagation decoder. Simulation results show that the practical codes require no more than 0.46 extra bits at moderate rates and no more than 0.7 extra bits at low rates from the theoretical bounds.