Method for operating a communication system and a communication system with training means

• US 6,967,994 B2
• Filed: 09/07/2001
• Issued: 11/22/2005
• Est. Priority Date: 09/20/2000
• Status: Expired due to Term

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Agere Systems Incorporated (Broadcom, Inc.)
• Inventors: Mud, Rienk, Van Bokhorst, Henk, Kopmeiners, Robert John, Boer, Jan, Kriedte, Kai Roland
• Primary Examiner(s): Chin, Stephen
• Assistant Examiner(s): Lu, Jia
• Application Number:
  US09/948,531
• Publication Number:
  US 20020048317A1
• Time in Patent Office: 1,537 Days
• Field of Search: 375/219, 375/316
• US Class Current: 375/219
• CPC Class Codes: H04L 1/0006 by adapting the transmission format

Abstract

A system for operating a communication system comprising one or more transmitters and receivers. The transmitted signals are provided with a preamble for training the receiver and/or the transmitter being in communication. The quality of the received signal is measured and compared with a threshold. If the quality is higher or lower than said threshold, a short preamble processing or a long preamble processing, respectively, is used. More than one threshold and associated pairs of preambles having different length may be used.

Claims

1. A method for operating a wireless communication system having one or more transmitters and receivers, in which the transmitted signals are provided with a preamble for training the receiver and/or the transmitter, the method comprising:

measuring the quality of the received signal,

comparing the measured quality of the received signal to a threshold, and

performing a predefined short preamble or a predefined long preamble processing in response to the comparing step.

2. The method according to claim 1, wherein more than one threshold and more than two preambles having different length are used.

3. The method according to claim 1, wherein a signal-to-noise ratio is used as the quality measure of the received signal.

4. The method according to claim 1, wherein the signal strength is used as the quality measure of the received signal.

5. The method according to claim 1, wherein the signal peak value is used as the quality measure of the received signal.

6. The method according to claim 1, wherein the quality measure is derived from an automatic gain control.

7. The method according to claim 1, wherein a fallback algorithm is used.

8. The method according to claim 7, wherein based on propagation conditions the optimum data rate is determined and used.

9. The method according to claim 6, wherein based on propagation conditions a correct working preamble length is selected.

10. The method according to claim 7, wherein a predetermined number of misses of the detection of the signal is used as measure for the propagation conditions.

11. The method according to claim 1, wherein if the quality of the received signal is higher than the threshold then predefined short preamble processing is selected, otherwise predefined long preamble processing is selected.

12. The method according to claim 7, wherein the transmitter is forced to use the long preamble in the absence of an acknowledgement of the correct propagation to be received the receiver.

13. The method according to claim 1, wherein before the step of performing short or long preamble processing, the step of performing antenna diversity is used.

14. A communication system having a transmitter and a receiver, in which a transmitted signal is provided with a preamble for training the receiver and/or the transmitter, the communication system comprising:

a receiver having a quality measuring device for receiving the received signal and for generating a quality measure signal, the receiver further having a comparator coupled to the quality measuring device for comparing the quality measure signal to a threshold signal, in which in response to the comparison, a short preamble or long preamble processing is used.

15. The communication system according to claim 14, wherein more than one threshold and more than two preambles having different length are used.

16. The communication system according to claim 14, wherein the signal-to-noise ratio is used as quality measure signal.

17. The communication system according to claim 14, wherein the signal strength is used as quality measure signal.

18. The communication system according to claim 14, wherein the signal peak value is used as quality measure signal.

19. The communication system according to claim 14, wherein the quality measure signal is derived from an automatic gain control device.

20. The communication system according to the claim 14, wherein a fallback device is used.

21. The communication system according to claim 20, wherein the fallback device is provided with a data rate adjusting device controlled by an acknowledgement signal, the acknowledgement signal identifying whether the transmitter signal was successfully received.

22. The communication system according to claim 21, wherein the fallback device is provided with a preamble selecting device that selects the correct working preamble length based on propagation conditions.

23. The communication system according to claim 21, wherein it is started with a long preamble.

24. The communication system according to claim 21, wherein the transmitter and receiver are forced to use the long preamble in the absence of an acknowledgement signal identifying successful reception of the transmitter signal.

25. The communication system according to claim 14, wherein before the decision of using the short or long preamble processing, antenna diversity is used.