FDD forward link beamforming method for a FDD communications system
US6134261A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 5, 1998 |
| Grant date | Oct 17, 2000 |
| Priority date | — |
| Expiry date | Mar 5, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B7/0617
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A highly bandwidth-efficient communications method is disclosed, to maximize the signal-to-interference-noise ratio (SINR) of transmissions from a base station to a remote station in a wireless communications system. The method is used for base stations that have a plurality of antenna elements that are capable of spatial beam steering by altering the relative phase of transmission of signals from the respective elements. The method of the invention is based on providing calibration frames that sequentially transmit calibration bursts from the respective antenna elements for a particular destination remote station. The calibration bursts include 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. The plurality of calibration bursts are part of a transmission frame having a reference phase. The remote station receives the calibration bursts and measures values re…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.