Soft handoff for OFDM
US7042858B1 · kind B1 · utility
Inventors
Key dates
| Filing date | Mar 22, 2002 |
| Grant date | May 9, 2006 |
| Priority date | — |
| Expiry date | Oct 14, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04W36/304
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
The present invention relates to soft handoffs in an OFDM system. Each mobile terminal measures pilot signal strengths of transmissions from adjacent base stations. If the pilot signal strength for a base station exceeds the defined threshold, that base station is added to an active set list. Each mobile terminal notifies the base stations of their active set lists. By providing the set list to the base station controller and the servicing base station, the mobile terminal identifies the sole servicing base station or triggers a soft handoff mode when multiple base stations appear on the active set list. The soft handoff mode uses a combination of scheduling and space-time coding to affect efficient and reliable handoffs.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.