Improved interoperable 2.4 kb/s LPC using sinusoidal transform coder techniques

It is shown that it is possible to code the parameters of the sinusoidal transform coder (STC) according to Government Standard FS-1015. To accommodate the standard, the voicing probability was quantized to 1 b, and the selection of the voicing threshold was a major focus of the experimental work. Preliminary experiments with the various interoperability configurations have indicated a potential improvement in quality in the fully interoperable STC/STC and LPC/STC modes (C2, D2).<>