Apparatus for synchronizing a voice coder and a voice decoder of a vector-coding type
US5765128A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 2, 1995 |
| Grant date | Jun 9, 1998 |
| Priority date | — |
| Expiry date | Oct 2, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L7/041
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
An apparatus synchronizes a voice coder and a voice decoder which are of the vector-coding type in order to prevent a false synchronization even when a signal having the same period as a string of synchronizing bits is inputted. A noise component adding unit adds a noise component to an input voice signal. Therefore, even if the input voice signal has the same period as that of a string of synchronizing bits and is completely periodic, the periodicity of the input voice signal is lost by the added noise component. Based on the input voice signal which is no longer periodic, a vector-coding unit, a quantizing signal vector generating unit, and a code book index transmitting unit generate code book indexes and transmit the generated code book indexes to a voice decoder. Therefore, the voice decoder is prevented from developing a false synchronization.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.