Title :
A Comparison of Orthogonal Transformations for Digital Speech Processing
Author :
Campanella, S.J. ; Robinson, Guner S.
Author_Institution :
COMSAT Labs., Md.
fDate :
12/1/1971 12:00:00 AM
Abstract :
Discrete forms of the Fourier, Hadamard, and Karhunen-Loève transforms are examined for their capacity to reduce the bit rate necessary to transmit speech signals. To rate their effectiveness in accomplishing this goal the quantizing error (or noise) resulting for each transformation method at various bit rates is computed and compared with that for conventional companded PCM processing. Based on this comparison, it is found that Karhunen-Loève provides a reduction in bit rate of 13.5 kbits/s, Fourier 10 kbits/s, and Hadamard 7.5 kbits/s as compared with the bit rate required for companded PCM. These bit-rate reductions are shown to be somewhat independent of the transmission bit rate.
Keywords :
Bit rate; Delta modulation; Discrete transforms; Feedback; Fourier transforms; Image processing; Noise reduction; Phase change materials; Speech processing; Vocoders;
Journal_Title :
Communication Technology, IEEE Transactions on
DOI :
10.1109/TCOM.1971.1090777