The application of subband coding to improve quality and robustness of the sinusoidal transform coder
R. McAulay, Thomas F. Quatieri · IEEE International Conference on Acoustics Speech and Signal Processing · 1993
In an attempt to improve the performance of the sinusoidal transform coder (STC) in the presence of channel errors, a structure evolved that was similar to a subband coder. Using some new ideas for subband coding, such as vector quantization of the subband energies and adaptive bit allocation based on the decoded energies, a new quantization algorithm for STC evolved that was not only more robust in channel errors, but led to improved quality, particularly at the 2400 bit/s data rate. It may be possible further to improve the speech quality at this rate by using vector quantization to code the shape of the subband channel gains.>