The Algorithm Of Mixed Excitation Speech Coding And Its Software Simulation

Speech Coding is a very important technology in the field of Digital Communication. With the help of Speech Coding, the same channel can transmit more informatioin. In general, Speech Coding has three major directions: Waveform Coding, Parametric Coding and Hybrid Coding. With the development of Digital Communication, the research about Hybrid Coding is becoming more and more popular, and it must have a wide application in the area of Secure Communication, Voice Mail, Network Communication, IP Telephone, and so on.In this paper, a simplified algorithm is brought forward at the basis of Mixed Excitation Linear Prediction (MELP). It simplifies the complexity of the extraction of the Pitch and uses a new U/V (Unvoiecd/Voiced) decision algorithm. The quality of synthesized speech it gets is almost the same with the original algorithm. This paper has mainly done the following work at the basis of traditional MELP algorithm:First of all, after careful study, we know that the Integer Pitch, Fractional Pitch and the Final Pitch are very close to each other.Therefore, the Integer Pitch is used as the Final Pitch in order to simplify the algorithm.Second, this paper uses a new U/V (Unvoiecd/Voiced) decision algorithm.Third, improves the decoder algorithm of MELP.Finally, the new algorithm is simulated at the software platform of Matlab and compares the Synthesized Speech with the Original Speech of Waveform, Spectrogram and Chromatogram in order to illustrate the performance of the new algorithm.