MIMO wireless precoding system robust to power imbalance
US7629902B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 30, 2008 |
| Grant date | Dec 8, 2009 |
| Priority date | — |
| Expiry date | May 30, 2028 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L25/0242
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
The present invention relates to methods and apparatus for preventing power imbalance in a multiple input multiple output (MIMO) wireless precoding system. According to one aspect of the present invention, a codebook is constructed with a first subset of codewords that are constant modulus matrices, and a second subset of codewords that are non-constant modulus matrices. A mapping scheme is established between the first subset of codewords and the second subset of codewords. When a unit of user equipment feeds back a first codeword that is a non-constant modulus matrix, the Node-B may replace the first codewords with a second codeword that is selected from the first subset of codewords and that corresponds to the first codeword in accordance with the mapping scheme.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.