Multistage beamforming of multiple-antenna communication system
US9806926B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 28, 2014 |
| Grant date | Oct 31, 2017 |
| Priority date | — |
| Expiry date | Apr 29, 2035 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L5/0051
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A multistage beamforming circuit includes a data unit that implements a frequency domain beamforming stage and a remote radio head that implements a time-domain broadband beamforming stage. The data unit implements the frequency domain beamforming stage by converting K received data streams into M precoding output streams in a frequency-domain. The data unit is configured to transform the M output streams to M OFDM time-domain signals. The remote radio head, or integrated radio unit is configured to implement a time-domain broadband beamforming stage by converting the M OFDM time-domain signals into N transmit streams of time-domain samples. The remote radio head, or integrated radio unit includes a transmit antenna array configured to transmit the N transmit streams that together form broadcast beams and user-specific beams. The antenna array includes a plurality of physical antennas. The number N of transmit streams is greater than the number M of precoding output streams.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.