System and method for transmitting highly correlated preambles in QAM constellations

• US 20040001448A1
• Filed: 06/28/2002
• Published: 01/01/2004
• Est. Priority Date: 06/28/2002
• Status: Abandoned Application

• Current Assignee: Harris Corporation (L3Harris Technologies, Inc.)
• Original Assignee: Harris Corporation (L3Harris Technologies, Inc.)
• Inventors: Preston, Shawn E., Lopez, Guy, Schafer, David C.
• Application Number:
  US10/183,384
• Publication Number:
  US 20040001448A1
• Time in Patent Office: Days
• US Class Current: 370/280
• CPC Class Codes: H04L 27/3411 reducing the peak to average power ratio or the mean power of the constellation; Arrangements for increasing the shape gain of a signal set

Abstract

A method for transmitting a data signal where the data signal includes a preamble portion preceding a payload portion that reduces harmonic spikes is presented. The method reduces the transmission power for portions of bursty data signal that contain highly correlated or repetitive preamble sequences relative to the transmission power that contain non-highly correlated or repetitive payload sequences. The resultant average output power of the preamble sequences is approximately equal to the average output power of the payload sequences.

Claims

1. In a communication system, a method for transmitting a data signal where the data signal includes a preamble portion preceding a payload portion, the improvement comprising decreasing the output power of the transmitter when transmitting the preamble portion.

2. The method of claim 1, wherein the average output power of the transmitter when transmitting the preamble is equal to or less than the average output power of the transmitter when transmitting the payload portion.

3. The method of claim 2 where system is TDD

4. The method of claim 3, wherein the system is adaptive

5. The method of claim 4, wherein the system is for broadband short distance radio communication of bursty data between one computer network to another computer network.

6. The method of claim 2, wherein the average power of the payload portion is estimated prior to transmission

7. The method of claim 2, wherein the average power of the preamble portion is estimated prior to transmission.

8. The method of claim 7, wherein the average power of the preamble is estimated as a sine wave

9. In a communication system, a method for transmitting highly correlated or repetitive symbols and non highly correlated symbols in an average power-limited environment, the improvement of decreasing the output power of the transmitter when transmitting the highly correlated symbols relative to the output power of the transmitter when transmitting the non highly correlated symbols.

10. The method of claim 9, wherein the average output power of the transmitter when transmitting the highly correlated symbols is equal to or less than the average output power of the transmitter when transmitting the non-highly correlated symbols.

11. The method of claim 10 where system is TDD

12. The method of claim 11, wherein the system is adaptive

13. The method of claim 12, wherein the system is for broadband short distance radio communication of bursty data between one computer network to another computer network.

14. The method of claim 10, wherein the average power of the payload portion is estimated prior to transmission

15. The method of claim 10, wherein the average power of the preamble portion is estimated prior to transmission.

16. The method of claim 15, wherein the average power of the preamble is estimated as a sine wave

17. In a method for reducing out of bandwidth harmonic spikes during transmission caused by a sequence of highly correlated symbols common in a preamble portion of bursty type data, the improvement comprising transmitting the highly correlated symbols at a lower transmitter power than when transmitting the non-highly correlated symbols common in a payload portion.

18. The method of claim 17, wherein the average output power of the transmitter when transmitting the highly correlated symbols is equal to or less than the average output power of the transmitter when transmitting the non highly correlated symbols.

19. The method of claim 18, wherein the average power of the non-highly correlated symbols is estimated prior to transmission

20. The method of claim 18, wherein the average power of the sequence of highly correlated symbols is estimated prior to transmission.

21. The method of claim 20, wherein the average power of the sequence of highly correlated symbols is estimated as a sine wave

22. A method of transmitting frames of data, where the frames of data include a preamble and a payload portion, the improvement wherein the average power of the transmitted signal representing the preamble is less than or equal to the average power of the transmitted signal representing the payload portion.

23. The method of claim 22, where the preamble portion comprises highly correlated or repetitive symbols.

24. The method of claim 23, wherein the average power of the payload portion is estimated prior to transmission

25. The method of claim 23, wherein the average power of the preamble portion is estimated prior to transmission.

26. The method of claim 25, wherein the average power of the preamble portion is estimated as a sine wave

27. The method of claim 23, wherein the frames of data include a ramp up portion between the preamble and the payload portions.

28. The method of claim 27, wherein the frames of data include another ramp up portion prior to the preamble portion.

29. The method of claim 22 wherein the preamble portion is transmitted at 4 QAM

30. The method of claim 29, wherein the payload portions is transmitted at 4 QAM or higher.

31. The method of claim 30, wherein the payload portion and preamble portions are transmitted at different QAM rates.