Radio communications system and method with increased transmission capacity based on frequency twisted waves
US9712367B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 10, 2015 |
| Grant date | Jul 18, 2017 |
| Priority date | — |
| Expiry date | Jun 10, 2035 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/26362
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A method of implementing Orbital Angular Momentum (OAM) for radio communications in general and LTE in particular. Common prior art so far recreate the vorticity (axial rotation of the Poynting vector) by using ring-shaped antenna arrays. This application proposes to create the vorticity in signal processing without the need of any space diversity (i.e. work with a single antenna). An Hilbert transform is applied in frequency domain to the Fourier transform of the analytical representation of a band-limited OFDM signal. The Hilbert transform is then approximated by a development in series into orthogonal twisted modes. This can be seen as an inverse Fourier transform of the complex analytical signal. Therefore an OAM IFFT based transmitter is proposed where parallel IFFTs are performed for each OAM mode and superimposed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.