Lower Bounds on the Rate-Distortion Function of LDGM Codes

Abstract-- We analyze the performance of low-density generator matrix (LDGM) codes for lossy source coding. We first develop a generic technique for deriving lower bounds on the effective rate-distortion functions of binary linear codes. This result provides a source coding analog of a classical result due to Gallager for channel coding over the binary symmetric channel. We illustrate this method for the ensemble of check-regular lowdensity generator matrix (LDGM) codes by deriving an explicit lower bound on its rate-distortion performance as a function of the check degree.

• Type: Journal
• Year: 2008
• Where: CORR
• Authors: Alexandros G. Dimakis, Martin J. Wainwright, Kannan Ramchandran
• Keywords: CORR 2008, Education, Generator Matrix, Low-density Generator Matrix, Lower Bound