Title :
A Comparison of Optimum and Logarithmic Quantization for Speech PCM and DPCM Systems
Author :
Stroh, Raymond W. ; Paez, Mario D.
Author_Institution :
Dept. of Electr. Eng., North Carolina State Univ., Raleigh, NC, USA
fDate :
6/1/1973 12:00:00 AM
Abstract :
Two quantization rules, optimum (minimum mean-square error) and logarithmic companding, are compared for application to digital speech transmission. Comparison is made on the basis of signal-to-quantizing noise ratio (S/N), subjective quality judgments, idle channel noise, and dynamic range. These quantizers are considered in both PCM and differential PCM configurations. A computer algorithm is described that yields the optimum quantizer levels for a given speech record. It has been found that the improvement in S/N which optimum quantization affords over conventional logarithmic quantization is offset by the greater idle channel noise and smaller dynamic range (range of talker volumes handled with a lower limit on S/N) of the optimum law.
Keywords :
DPCM systems; PCM systems; Quantization; Voice communication systems; Application software; Computer errors; Dynamic range; Noise level; Phase change materials; Pulse modulation; Quantization; Signal to noise ratio; Speech; Testing;
Journal_Title :
Communications, IEEE Transactions on
DOI :
10.1109/TCOM.1973.1091720