Method for hiding loss package and system thereof

Abstract

The invention discloses a method for packet loss concealment and a system therefor. The method comprises the following steps: according to the periodicity of a pitch and a phase of a signal, a section of time domain signal is taken in a previous frame and a later frame of a lost signal respectively for the conversion from time domain to frequency domain to obtain a previous frame frequency domain coefficient and a later frame frequency domain coefficient; amplitude values of the previous frame frequency domain coefficient and the later frame frequency domain coefficient are interpolated to obtain amplitude values of frequency domain coefficients of a plurality of reconstruction signals; phases which are most similar to those of the reconstruction signals are taken in the previous frame or the later frame respectively to serve as phase values of the frequency domain coefficients of the reconstruction signals; the conversion from frequency domain to time domain is performed according to the amplitude values of the frequency domain coefficients of the reconstruction signals to obtain time domain signals of the reconstruction signals, and time domain signals of the reconstruction signals are superposed to restore the lost signal. The adoption of the method can improve the accuracy of the period of the reconstruction signals and the matching precision of the phase.

Description

technical field [0001] The present invention relates to the field of communications, in particular to a method and system for concealing packet loss Background technique [0002] IP networks were originally designed for the transmission of data streams that consist of larger packets that do not need to be delivered reliably in real time, while the transmission of voice requires smaller packets to be delivered reliably in real time. When a voice packet is dropped in transit, there is usually no time to retransmit the dropped packet. Similarly, when a voice packet has gone through a long route and cannot arrive in time when it needs to be played, this packet has lost the meaning of existence. Therefore, in a VoIP (Voice over IP, IP-based voice call) system, when a voice packet cannot arrive in time or cannot arrive, it is considered lost. [0003] Network packet loss is the main reason for the degradation of voice service quality in network transmission. Can be used to reco...

AI Technical Summary

Problems solved by technology

[0031] Combined with the packet loss concealment process provided by the existing technology and figure 1 It can be seen from the 103 waveform diagram in the figure that since the window shift is set to half of the frame length, the window length is the frame length, and each frame corresponds to 2 window shifts, thus generating 2 periods of the reconstructed signal, resulting in the generated speech signal The period may not match the actual signal; and, because the position setting of the Fourier transform window does not take into account the phase of the previous and subsequent frames, the phase of the reconstructed signal does not match the phase of the previous and subsequent frames

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