MIMO wireless communication system
US6870515B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 11, 2001 |
| Grant date | Mar 22, 2005 |
| Priority date | — |
| Expiry date | Apr 5, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B7/0891
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
Previous MIMO systems have used spatially diverse antenna elements in order not to reduce the number of orthogonal channels that can be realized. The present invention recognizes that this leads to large antenna sizes, as compared to multiple beam antenna systems which use closely spaced antenna elements. In order to provide a compact antenna unit, while still allowing a MIMO system to be exploited, the present invention recognizes that polarization diversity only can be used in a MIMO system without the need for spatially diverse antenna elements. Closely spaced antenna elements are used and this enables a compact MIMO antenna unit to be provided. In addition, such MIMO systems with polarization diversity but no spatial diversity can advantageously be used in line of sight situations and also combined with multi-beam antenna systems to further increase capacity.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.