Speech Coding at 4.8 kb/s with an Improved Pitch Filter
Ian Yasheng, P. Kabal · 1994
The reconstructed speech quality in a low bit-rate CELP coder is very dependent on the performance of the pitch filter. In this paper, we present an improved pitch filter, a fractional pseudethree-tap pitch synthesis filter, which performs better than a conventional one-tap pitch filter. We discuss the frequency response of the improved pitch filter. We explore stability issues for three-tap pitch filters in a CELP coder. We have incorperated a fractional pseudethree-tap pitch filter into a 4.8 kb/s CELP speech coder. Both objective and subjective quality have been improved with the fraction pseudethree-tap pitch filter. 1.