Pitch prediction with fractional delays in CELP coding

Time-domain eoders use long-term predietors to exploit the quasiperiodie strueture of voiced speech. However, one major drawbaek with classical predictors is the restriction of the delay to integer values, reducing the performance especially when the pitch period is short. This paper presents an extension of the prediction technique to encompass non-integer delays enabling more aeeurate representation of quasi-periodie segments and an increased flexibility in the design of long-term predictors. The use of long-term predictors with fractional delays in CELP coding produces an enhancement of the harmonic structure in high frequencies and an improvement of quality for female spcakers.