On the use of simulated annealing for error protection of CELP coders employing LSF vector quantizers

Examines the application of simulated annealing to assign indices to the output levels of a vector quantizer (VQ). The quantizer is used for the LSF parameter representation of the short-term predictor of a CELP coder. Three classes of error protection and a 0.1 channel error rate are considered. Simulation results show that the use of the index assignment provides significant gains both in terms of average distortion as well as in terms of reduction of large outliers. The improvements afforded by the index assignment, however, were not significant when the VQ was used inside the structure of a CELP coder