On the DPCM compression of Gaussian autoregressive sequences

Differential pulse-coded modulation (DPCM) encoding of Gaussian autoregress ive (AR) sequences is considered. It is pointed out that DPCM is rate-disto rtion inefficient at low bit rates. Simple filtering modifications are prop osed and incorporated into DPCM, A rate-distortion optimization framework t hat results in optimal filters is presented. It is shown that the designed filters take advantage of "less significant" process spectral components in order to achieve superior rate-distortion performance, Design equations ar e derived, issues related to optimization and complexity addressed. It is s hown that simple DPCM systems with the proposed modifications significantly outperform their standard counterparts.