Apparatus and methods for controlling short code timing offsets in a CDMA system
US6813257B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 26, 2000 |
| Grant date | Nov 2, 2004 |
| Priority date | — |
| Expiry date | Jul 23, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B2201/70701
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A CDMA cellular communications network (400, FIG. 4) includes one or more aircraft (410), which relay pilot channel and control channel signals between base transceiver stations (BTS's 406, 413) and subscriber units (401). Over the control channel, the BTS transmits a handoff candidate list to the subscriber units. The handoff candidate list identifies candidate BTS's to which the subscriber unit, theoretically, could hand off. In addition, the list indicates at which offsets the subscriber units should search for short codes transmitted by the candidate BTS's over the pilot channel. Based on the path length between the BTS, aircraft, and subscriber unit, the candidate BTS's actually generate their short codes at an offset that is equal to or earlier than the offset reported to the subscriber unit by some delta. In addition, the BTS's can impose a variable delay on the generated short code bits to compensate for variations in the path delay as the aircraft flies in its flight pattern.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.