| 摘要 |
A synthesizer for a channel vocoder for the transmission of speech with considerable frequency band reduction in digital technology provides a reduction of circuit expense. This is accomplished, given non-recursive filters having finite impulse response, not with a weighting of the pulse-shaped excitation variable with the transmitted envelope values of the spectral channels, but with a time variance of the filters by weighting their filter coefficients with the transmitted envelope values. In addition, with proper dimensioning of the filter coefficients, an optimum speech quality of synthesized speech is obtained at the output of the synthesizer even given elimination of the transmission of a voiced/voiceless signal. |
