| 摘要 |
The invention provides a novel method for ensuring the phase continuity in transitions from a frame coded by a waveform matching coder to a frame coded using a parametric speech coder in hybrid speech coders. In the proposed method, a phase estimate is derived for the end of the frame modeled by a waveform matching coder. Preferably, the phase estimate is derived from a reconstructed excitation signal of a linear prediction (LP) analysis. For the succeeding frame modeled by a parametric coder, conventional methods are then used for interpolation of the phase characteristic. By using the proposed method, discontinuities due to phase errors are avoided in the reconstructed speech signal. Further, the invention provides a method for detecting misalignments of succeeding coded by waveform matching speech coding and parametric speech coding. Additionally, communication terminals, a network device and a system are introduced which are able to operate the presented methods.
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