Title :
Smoothed DPCM codes
Author :
Gibson, Jerry D. ; Chang, Wen-Whei
Author_Institution :
Dept. of Electr. Eng., Texas A&M Univ., College Station, TX, USA
Abstract :
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 IDPCM 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
Keywords :
codes; encoding; pulse-code modulation; speech analysis and processing; code generators; differential pulse code modulation; interpolative DPCM; listening tests; minimum mean squared error; smoothed DPCM codes; sound spectrograms; speech; synthetic sources; tree searching; Acoustic testing; Decision trees; Decoding; Delay; Modulation coding; Pulse generation; Pulse modulation; Smoothing methods; Spectrogram; Speech coding;
Conference_Titel :
Global Telecommunications Conference and Exhibition 'Communications Technology for the 1990s and Beyond' (GLOBECOM), 1989. IEEE
Conference_Location :
Dallas, TX
DOI :
10.1109/GLOCOM.1989.64270
