Time-varied pitch gain predictor for low bit rate speech coders

The long-term predictor (LTP) can effectively reduce the redundancy of the quasi-periodicity of speech signals. Traditional pitch predictors in linear predictive coding systems are developed by assuming that pitch gains are constant in ea(h processing subframe. In this paper, we introduce a time-varied prediction gain to achieve a better representation of speech periodicity than the traditional approach, Due to the non-stationary. variation of speech. the proposed LTP method can trace the detailed fluctuation of speech amplitude in both transient and stationary periods, Simulation results show that the proposed first-order varied-gain pitch predictor obtains a near speech quality as the fifth-order pitch predictor of the G.723.1 coder does: however. the former requires much lower computation than the latter.