Synchronization preamble method for OFDM waveforms in a communications system
US6643281B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Mar 5, 1998 |
| Grant date | Nov 4, 2003 |
| Priority date | — |
| Expiry date | Mar 5, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L5/026
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A highly bandwidth-efficient communications method is disclosed that enables remote stations to synchronize in time and frequency to their serving base station. The invention enables a base station and its remote stations in a cell to synchronize in a noisy environment where signals interfere from other base stations and remote stations in other cells. The base station forms a forward synchronization burst that includes a plurality of tone frequencies arranged in a distinctive orthogonal frequency division multiplexed pattern unique to the base station. The unique pattern enables a remote station to distinguish the base station's bursts from other signals present in a crowded area. The distinctive orthogonal frequency division multiplexed pattern can be a Hadamard code pattern, for example. When the a base station has received a signal on a reverse link from a remote station, having significant interference, the base station selectively forms a request signal requesting the remote station to respond with a reverse synchronization burst that includes a plurality of tone frequencies arranged in the same distinctive orthogonal frequency division multiplexed pattern. The base station t…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.