METHOD AND APPARATUS FOR CONCEALING PACKET LOSS, AND APPARATUS FOR TRANSMITTING AND RECEIVING SPEECH SIGNAL

摘要

PURPOSE: A method and an apparatus for concealing packet loss, and an apparatus for transmitting and receiving a speech signal are provided to improve accuracy when restoring a lost frame of a speech signal transmitted through a packet network, thereby providing improved speech quality. CONSTITUTION: A method for concealing packet loss in a speech signal decoder comprises the following steps. When a received current frame has loss, a voiced sound probability is calculated by using an excited excitation signal and a pitch value in a received previous frame(S409). A random excitation signal generated from an excitation signal decoded in the received previous frame with loss is generated(S411). A noise excitation signal is generated by a pitch excitation signal(S413). A weighted value determined by the voiced sound probability is applied to the pitch excitation signal and the noise excitation signal. The excitation signal about the lost current frame is restored(S405).