Optimum Source Codec Design in Coded Systems and Its Application for Low-Bit-Rate Speech Transmission
Hong Yuan Xiao, Branka S. Vucetic · 2000
this paper, we propose a generalized algorithm that designs an optimum VQenc der/dec der pair in systems withc hannelc ding based on an AWGNc hannel model. We first give the expression of end-to-end distortion for a generalc ded system and show that this end-to-end distortion is dominated by the distribution of thec hanneldec der soft-output vecR9Rj Then, we derive this distribution and optimize both the VQ enc der and dec der by minimizing the end-to-end distortion. Furthermore, we applied the proposed algorithm to a VQ basedc de-exc9--9 linearpredicNk-- (VQ-CELP) speec h transmission system for designing optimum speec h parameterenc der/dec der pairs over a noisyc hannel.Sinc the speec h signals at thereck6 er are synthesized by the transmitted parameters, the proposed