An adaptive transform coding system with short primary blocklengths and frequency domain quantization using feedback adaptation

An adaptive transform coding system with very short primary blocklengths is briefly described. The applicability of feedback adaptive quantization of transform coefficients in this system is studied. The results show that the system has a speech quality comparable to that of other more complex systems, for the same bitrate, as both objective measurements and informal listening tests show at a bitrate of 14.3 kb/s (including 300 b/s side information). The system is very suited for simple hardware implementation. Future scope for data reduction using short blocks in ATC systems is summarized.