Coherent transmission from distributed wireless transmitters
US9031180B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 5, 2012 |
| Grant date | May 12, 2015 |
| Priority date | — |
| Expiry date | Oct 5, 2032 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L25/0204
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
In one aspect, a distributed coherent transmission system enables transmissions from separate wireless transmitters with independent frequency or clock references to emulate a system where all the transmitters share a common frequency or clock reference. Differences in frequency and/or phase between transmitters are addressed by suitably precoding signals before modulation at one or more of the transmitters based on a synchronizing transmission from one of the transmitters (e.g., a master transmitter) received at a corresponding receiver sharing the frequency or clock reference with each of the one or more transmitters. Such a distributed coherent transmission system can allow N single-antenna transmitters with independent frequency or clock references to emulate a single N-antenna Multi Input Multi Output (MIMO) transmitter, or implement schemes such as distributed superposition coding or lattice codes that require coherence across separate transmitters.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.