Research And DSP Implement Of A Low Bit Rate Speech Coding Based On MBE

With the rapid development of military communication, mobile communication and Internet, speech communications are constantly updated and integrated. As an important part of digital speech communication, speech coding is also updating in the pursuit of the best possible quality of synthesized speech with the lowest possible coding rates. Thus, the low rate speech coding has been the main direction of speech coding technology, speech coding with low rate and high-quality would be the research hotpot.Firstly, a review of speech coding was given, including the research stats, development trend and the existing problems. Then, a detail analysis of the low rate speech coding technology was provided, with focus on the characters of multi-band excitation (MBE) speech model as well as the methods of estimating the speech model parameters and synthesizing speech with these estimated parameters. Besides, based on the studies of MBE model, the analysis of speech coding algorithm was provided as well. Finally, based on the existing research achievements, a new speech coding algorithm with MSVQ in the quantitative part was proposed, which further reduced the bit error rate and improved the qualities of synthetic speech so as to make it with better clarity and intelligibility.In this thesis, the simulation of the algorithm is given in VC environment with C language. The listening test shows the synthesized speech is of high intelligibility at the rate of 2.45kps. Finally, the implement the algorithm is implemented with DSP, using TMS320C5510DSK as the hardware development platform.