关键词: 语音编码, 分数基音, 基音估计, 插值法, 多项式拟合

Abstract: A low complexity fractional pitch estimation algorithm for speech coding based on polynomial fitting theory is presented.Giving a series of long term prediction gain at integer sampling points，the fractional pitch is estimated by quadratic fitting at the proximity of the maximum point.Compared to the known algorithm based on sampling function interpolation，it eliminates constant interpolation table，interpolations，exhaustive searching，and comparison operations，with a complexity independent of interpolation factor—1/25 of that of the known algorithm in typical cases.The objective and subjective tests of a speech coder using the proposed algorithm show equivalent performance in terms of long term prediction gain and speech quality as the known algorithm.

Key words: speech coding, fractional pitch, pitch estimation, interpolation, polynomial fitting