Smoothed DPCM codes

Jerry D. Gibson*, Wen-Whei Chang

*Corresponding author for this work

Research output: Contribution to conferencePaperpeer-review

1 Scopus citations


Minimum mean squared error (MMSE) fixed-lag smoothing is used in conjunction with DPCM (differential pulse code modulation) to develop a code generator employing delayed decoding. This smoothed DPCM (SDPCM) code generator is compared to DPCM and interpolative DPCM (IDPCM) code generators at rates 1 and 2 for tree coding several synthetic sources, as well as to a DPCM code/generator at rate 2 for speech sources. The (M, L) algorithm is used for tree searching, and SDPCM outperforms IDCPM and DPCM at rate 2 for synthetic sources with M = 1, 4, 8, and 12, and at rate 1 with M ≥ 4. For speech, SDPCM provides a slight improvement in MSE (mean squared error) over DPCM codes, which is also evident in sound spectrograms and listening tests.

Original languageEnglish
Number of pages5
StatePublished - 27 Nov 1989
EventIEEE Global Telecommunications Conference & Exhibition (GLOBECOM '89). Part 1 (of 3) - Dallas, TX, USA
Duration: 27 Nov 198930 Nov 1989


ConferenceIEEE Global Telecommunications Conference & Exhibition (GLOBECOM '89). Part 1 (of 3)
CityDallas, TX, USA


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