Improved discontinuous transmission speech coding algorithm based on MELP
Li Qian · Journal of Chongqing University of Posts and Telecommunications · 2014
In order to improve the utilization of transmission bandwidth in voice communication,this paper proposes a discontinuous transmission method based on mixed excitation linear prediction( MELP) vocoder. Firstly,by using the algorithm of voice activity detection( VAD),the received signal is divided into voice frame and mute frame. The transitional frame is introduced when the voice frame is converted to mute frame. Voice frames and transitional frames are encoded at a normal rate,but mute frames are encoded into silence description( SID) frame at a lower rate,which is sent by a method of discontinuous transmission mode. The transmission frequency of SID frame is adjusted automatically according to the fluctuation of characteristic parameters of background noise in mute frames. Simulation results show that this method has better adaptability in the transmission of mute signal and the synthesized background noise presents good comfort and continuity in the auditory perception.