Synchronization and segment type detection method for data transmission via an audio communication system
US7912149B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 3, 2007 |
| Grant date | Mar 22, 2011 |
| Priority date | — |
| Expiry date | Nov 24, 2029 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L7/08
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A system and method for asynchronous data communication over a cellular communications network that allows the transmission of different types of data frames over a voice channel using a vocoder. The data frames include a synchronization signal and data segment, with the synchronization signal being selected in accordance with an attribute of the data segment so that, upon receipt of the data frame, the synchronization signal can be used by the demodulating modem to determine not only where the data segment begins, but also to identify what type of data segment is in the received data frame. The synchronization signals used have low cross-correlation and an auto-correlation function that approximates a unit impulse function to provide reliable transmission through the vocoder.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.