Packet loss concealment based on sinusoidal extrapolation

In this paper, a packet loss concealment scheme based on sinusoidal extrapolation is proposed. It is to be implemented at the receiver end of a packetized speech transmission system and conceals frame-erasures in a PCM waveform. The scheme operates on the source-filter components of the speech signal, which are obtained through Linear Prediction (LP) analysis. When one or more speech frames are missing, the LP residual and filter coefficients are extrapolated separately. The residual is extrapolated based on sinusoidal modeling of the last correct residual frame, whereas the latest filter is repeated and bandwidth expanded. The proposed scheme is compared to two benchmark systems by means of subjective testing. The benchmark systems are based on repetitions of the last pitch period; one operates on the source-filter components, the other directly on the speech signal. It is noted that the systems operating on the source-filter components are preferred by the listeners, and that the proposed system is clearly superior to both benchmark systems.