Title :
Integrated single-channel PCM encoder-filter combination
Author :
Höfelt, M. H H ; Janssen, D. J G ; Meeberg, L. V d
Author_Institution :
N. V. Philips, Eindhoven, The Netherlands
Abstract :
An encoder for use in PCM trunk transmission is presented. It consists of a 512 kHz Sigma-Delta Modulator followed by a 640th order non-recursive digital filter. The filter output, subsampled at 8 kHz, is compressed according to the A-law and multiplexed. The bandlimiting function of the filter complies with the CCITT Recommendations. Its higher frequency behaviour is such that noise in the band from 4 to 508 kHz contributes negligibly to the PCM output. The system is realized as an LSI circuit plus a few non-critical standard components for the delta modulator and a 2nd order active prefilter.
Keywords :
Circuit noise; Delta modulation; Delta-sigma modulation; Digital filters; Dynamic range; Finite impulse response filter; Frequency; Large scale integration; Niobium; Phase change materials;
Conference_Titel :
Acoustics, Speech, and Signal Processing, IEEE International Conference on ICASSP '77.
DOI :
10.1109/ICASSP.1977.1170339
