Improvement on plural unit selection and fusion

Plural unit selection and fusion is a successful method for concatenative synthesis. Yet its unit fusion algorithm is simple and requires improvement. Previous research on unit fusion is mainly involved in boundary smoothing and not quite suitable for the application mentioned above. Therefore, a high-quality unit fusion method is proposed in this paper. More accurate pitch frame alignment and primary unit selection are implemented. Besides, the fusion of pitch frames is performed on FFT spectra for less quality loss. Experiment results indicate that the proposed method evidently outperforms the baseline at an overall preference ratio of 54:17.