Method of reconstructing lost data in a digital voice transmission system and transmission system using said method
US4907277A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 27, 1988 |
| Grant date | Mar 6, 1990 |
| Priority date | — |
| Expiry date | Jun 27, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10L19/0204
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A method of reconstructing, at the receiving end, digital data defining an encoded voice signal segment lost in transmission between the transmitter and the receiver in a transmission system wherein a low-frequency signal such as a residual baseband signal is derived at the transmitting end from the signal to be encoded and is then distributed among several sub-bands whose sampled contents are quantized separately. The reconstruction method includes a step of analyzing the received signal to detect any missing segment thereof and, as the case may be, to initiate an analysis, within each sub-band, of the segment(s) adjacent to the lost segment, so as to generate a term relating to the period T.sub.(k) of the signal so analyzed and to reconstruct a segment of signal of period T.sub.(k) intended to be substituted for the lost segment. Cyclic redundancy is used to detect errors, and modulo sequence numbering identification is used to detect loss of packet.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.