Methods and apparatus for backwards compatible communication in a multiple antenna communication system using time orthogonal symbols
US7885177B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 30, 2004 |
| Grant date | Feb 8, 2011 |
| Priority date | — |
| Expiry date | Nov 6, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B7/0413
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A method and apparatus are disclosed for transmitting symbols in a multiple antenna communication system according to a frame structure, such that the symbols can be interpreted by a lower order receiver (i.e., a receiver having a fewer number of antennas than the transmitter). The disclosed frame structure comprises a legacy preamble having at least one long training symbol and N-1 additional long training symbols that are transmitted on each of N transmit antennas. The legacy preamble may be, for example, an 802.11 a/g preamble that includes at least one short training symbol, at least one long training symbol and at least one SIGNAL field. A sequence of each of the long training symbols on each of the N transmit antennas are time orthogonal. The long training symbols can be time orthogonal by introducing a phase shift to each of long training symbols relative to one another.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.