Minimum-variance phase prediction and frame interpolation algorithms for low bit rate sinusoidal speech coding

A number of improved algorithms for phase prediction and frame interpolation in the context of sinusoidal speech coding are presented. A minimum-variance sinusoidal phase estimation scheme is proposed. It is shown that reasonably accurate estimates for short-time sinusoidal phases corresponding to voiced frames can be obtained. In addition, improved algorithms for interpolation of sine wave parameters are presented which result in further reduction in bit rate while preserving the subjective equality of the reproduced speech at low bit rates. The performance of the proposed algorithms were evaluated on a large speech database and the results of statistical analysis are provided. The proposed algorithms were successfully integrated into a 2.4 kbps sinusoidal coder, where speech of good quality intelligibility, and naturalness was obtained