Claims
- 1. In a two-branch transmitter diversity wireless-communication system employing orthogonal frequency-division multiplexing, a method comprising:
transmitting a long-training symbol over a first channel during a long-training period, the long-training period being compliant with the Institute of Electrical and Electronics Engineers (IEEE) “Wireless Local Area Network (LAN) Medium Access Control (MAC) and Physical Layer (PHY) Specification”; transmitting the long-training symbol over a second channel during the long-training period; transmitting a complex conjugate of the long-training symbol over the first channel during a data period; transmitting a negative complex conjugate of the long-training symbol over the second channel during the data period; receiving the long-training symbols, the complex conjugate of the long-training symbol, and the negative complex conjugate of the long-training symbol; and extracting channel characteristics from the received long-training symbols, the complex conjugate of the long-training symbol, and the negative complex conjugate of the long-training symbol.
- 2. A method for estimating channel characteristics comprising:
transmitting a training symbol over a first channel during a first period; transmitting the training symbol over a second channel during the first period; transmitting a complex conjugate of the training symbol over the first channel during a second period; and transmitting a negative complex conjugate of the training symbol over the second channel during the second period.
- 3. The method of claim 2, wherein the transmitting the training symbol over the first channel during the first period comprises:
transmitting the training symbol over the first channel during a long-training period in a preamble of a physical layer convergence procedure (PLCP).
- 4. The method of claim 3, further comprising:
re-transmitting the training symbol over the first channel during the long-training period in the preamble of the PLCP.
- 5. The method of claim 2, wherein the transmitting the training symbol over the second channel during the first period comprises:
transmitting the training symbol over the second channel during a long-training period in a preamble of a physical layer convergence procedure (PLCP).
- 6. The method of claim 5, further comprising:
re-transmitting the training symbol over the second channel during the long-training period in the preamble of the PLCP.
- 7. The method of claim 2, wherein the transmitting the complex conjugate of the training symbol over the first channel during the second period comprises:
transmitting the complex conjugate of the training symbol over the first channel during a data period.
- 8. The method of claim 2, wherein the transmitting the negative complex conjugate of the training symbol over the second channel during the second period comprises:
transmitting the negative complex conjugate of the training symbol over the second channel during a data period.
- 9. The method of claim 2, further comprising:
transmitting additional training symbols over the first channel during other periods.
- 10. The method of claim 9, wherein the number of other periods is proportional to a number of channels.
- 11. The method of claim 2, further comprising:
transmitting additional training symbols over the second channel during other periods.
- 12. A method for estimating channel characteristics comprising:
receiving a first symbol, the first symbol comprising:
a training symbol transmitted over a first channel during a first period; and the training symbol transmitted over a second channel during the first period; receiving a second symbol, the second symbol comprising:
a complex conjugate of the training symbol transmitted over the first channel during a second period; and a negative complex conjugate of the training symbol transmitted over the second channel during the second period; and estimating channel characteristics from the received first symbol and the received second symbol.
- 13. The method of claim 12, wherein the estimating the channel characteristics comprises:
isolating first channel effects from the first symbol and the second symbol; and isolating second channel effects from the first symbol and the second symbol.
- 14. The method of claim 13, further comprising:
estimating characteristics of a first channel from the isolated first channel effects; and estimating characteristics of a second channel from the isolated second channel effects.
- 15. A system for estimating channel characteristics comprising:
logic adapted to transmit a training symbol over a first channel during a first period; logic adapted to transmit the training symbol over a second channel during the first period; logic adapted to transmit a complex conjugate of the training symbol over the first channel during a second period; and logic adapted to transmit a negative complex conjugate of the training symbol over the second channel during the second period.
- 16. The system of claim 15, wherein the logic adapted to transmit the complex conjugate of the training symbol over the first channel during the second period comprises:
logic adapted to transmit the complex conjugate of the training symbol over the first channel during a data period.
- 17. The method of claim 15, wherein the logic adapted to transmit the negative complex conjugate of the training symbol over the second channel during the second period comprises:
logic adapted to transmit the negative complex conjugate of the training symbol over the second channel during a data period.
- 18. The system of claim 15, further comprising:
logic adapted to transmit additional training symbols over the first channel during other periods.
- 19. A system for estimating channel characteristics comprising:
logic adapted to receive a first symbol, the first symbol comprising:
a training symbol transmitted over a first channel during a first period; and the training symbol transmitted over a second channel during the first period; logic adapted to receive a second symbol, the second symbol comprising:
a complex conjugate of the training symbol transmitted over the first channel during a second period; and a negative complex conjugate of the training symbol transmitted over the second channel during the second period; and logic adapted to estimate channel characteristics from the received first symbol and the received second symbol.
- 20. The system of claim 19, wherein the logic adapted to estimate channel characteristics comprises:
logic adapted to isolate first channel effects from the first symbol and the second symbol; and logic adapted to isolate second channel effects from the first symbol and the second symbol.
- 21. The system of claim 20, further comprising:
logic adapted to estimate characteristics of a first channel from the isolated first channel effects; and logic adapted to estimate characteristics of a second channel from the isolated second channel effects.
- 22. A system for estimating channel characteristics comprising:
means for transmitting a training symbol over a first channel during a first period; means for transmitting the training symbol over a second channel during the first period; means for transmitting a complex conjugate of the training symbol over the first channel during a second period; and means for transmitting a negative complex conjugate of the training symbol over the second channel during the second period.
- 23. The system of claim 22, wherein the means for transmitting the complex conjugate of the training symbol over the first channel during the second period comprises:
means for transmitting the complex conjugate of the training symbol over the first channel during a data period.
- 24. The method of claim 22, wherein the means for transmitting the negative complex conjugate of the training symbol over the second channel during the second period comprises:
means for transmitting the negative complex conjugate of the training symbol over the second channel during a data period.
- 25. The system of claim 22, further comprising:
means for transmitting additional training symbols over the first channel during other periods.
- 26. A system for estimating channel characteristics comprising:
means for receiving a first symbol, the first symbol comprising:
a training symbol transmitted over a first channel during a first period; and the training symbol transmitted over a second channel during the first period; means for receiving a second symbol, the second symbol comprising:
a complex conjugate of the training symbol transmitted over the first channel during a second period; and a negative complex conjugate of the training symbol transmitted over the second channel during the second period; and means for estimating channel characteristics from the received first symbol and the received second symbol.
- 27. The system of claim 26, wherein the means for estimating channel characteristics comprises:
means for isolating first channel effects from the first symbol and the second symbol; and means for isolating second channel effects from the first symbol and the second symbol.
- 28. The system of claim 27, further comprising:
means for estimating characteristics of a first channel from the isolated first channel effects; and means for estimating characteristics of a second channel from the isolated second channel effects.
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. provisional patent application serial No. 60/400,888, filed Aug. 1, 2002, which is incorporated herein by reference in its entirety.
Provisional Applications (1)
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Number |
Date |
Country |
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60400888 |
Aug 2002 |
US |