Linear prediction coefficient generation during frame erasure or packet loss
US5450449A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 14, 1994 |
| Grant date | Sep 12, 1995 |
| Priority date | — |
| Expiry date | Mar 14, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10L2019/0012
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A speech coding system robust to frame erasure (or packet loss) is described. Illustrative embodiments are directed to a modified version of CCITT standard G.728. In the event of frame erasure, vectors of an excitation signal are synthesized based on previously stored excitation signal vectors generated during non-erased frames. This synthesis differs for voiced and non-voiced speech. During erased frames, linear prediction filter coefficients are synthesized as a weighted extrapolation of a set of linear prediction filter coefficients determined during non-erased frames. The weighting factor is a number less than 1. This weighting accomplishes a bandwidth-expansion of peaks in the frequency response of a linear predictive filter. Computational complexity during erased frames is reduced through the elimination of certain computations needed during non-erased frames only. This reduction in computational complexity offsets additional computation required for excitation signal synthesis and linear prediction filter coefficient generation during erased frames.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.