Synchronizer and method therefor and communications system incorporating same
US6332008A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 13, 1998 |
| Grant date | Dec 18, 2001 |
| Priority date | — |
| Expiry date | Oct 13, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B1/7085
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
Users or subscribers of a spread spectrum synchronous communications system provide signals to the central station or base unit of that system, and receive signals therefrom. Proper synchronization among those users (and their signals) is needed to ensure proper operation of the system. To ensure proper synchronization among those users, the signal produced by each user is checked for presence and amount of any offset error. This is accomplished by using three despreaders for the signal for each user. For one such user, each such despreader for that user receives the spreading code for that user. However, the spreading code as received by any one such despreader is time-delayed with respect to the spreading code as received by the other two despreaders. Each such despreader receives the spreading code with a different amount of delay imposed on that spreading code. The outputs of the three despreaders are digitally combined (e.g. compared), or compared, to produce the offset estimate for that user. To reduce noise effects, the offset estimate is averaged over a predetermined time duration; alternatively, such averaging can be performed on the outputs of the despreaders, or at some …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.