A comparison of pitch prediction algorithms in forward and backward adaptive CELP systems

Compares several pitch prediction algorithms in forward and backward adaptive CELP system. Since a forward adaptation system uses the original speech signal to compute the filter parameters, while a backward adaptation system only uses the locally decoded speech which contains encoding noise, there are important differences between the two systems in the implementation of a pitch prediction algorithm. The authors investigated such pitch prediction strategies in these two systems in terms of the pitch prediction configuration, the pitch determination algorithms, and the pitch predictor adaptation technique