System for signal metric based receive selection

• US 8,224,272 B1
• Filed: 12/05/2007
• Issued: 07/17/2012
• Est. Priority Date: 12/15/2006
• Status: Active Grant

• Current Assignee: Marvell Asia Pte Limited (Marvell Technology Group Limited)
• Original Assignee: Marvell International Limited (Marvell Technology Group Limited)
• Inventors: Zhang, Hongyuan, Yang, Zhiyu, Shirali, Kedar, Salhotra, Atul
• Primary Examiner(s): TRAN, PABLO N
• Application Number:
  US11/999,482
• Time in Patent Office: 1,686 Days
• Field of Search: 455133-135, 455450-4522, 455512-513, 455 59- 62, 455/115.3, 455/226.2, 455/226.3, 455/67.13, 455/137, 455/227, 370/445, 370/450, 370/461, 370/462, 370/458, 370/459, 370/338, 370/447, 370/443, 370/44, 370/328
• US Class Current: 455/133
• CPC Class Codes: H04B 7/082 selecting best antenna path
• CPC Class Codes: H04L 23/02 adapted for orthogonal signalling
• CPC Class Codes: H04L 25/0262 Arrangements for detecting the data rate of an incoming signal
• CPC Class Codes: H04L 27/0012 arrangements for identifying the type of modulation
• CPC Class Codes: H04L 27/2071 in which the data are represented by the carrier phase, e.g. systems with differential coding

Abstract

A wireless networking receiver with digital antenna switching selects an antenna with an 802.11b signal based on a signal metric, such as the highest signal quality or highest peak amplitude. In one embodiment, the receiver comprises a plurality of antennas that may each receive one of a plurality of RF signals conforming to the IEEE 802.11b standard. The receiver may have multiple antennas for use with the IEEE 802.11n standard, but may receive signals conforming to the 802.11b standard. The receiver also comprises a carrier sense circuit configured to calculate a signal metric for each of the signals and further configured to generate a selection signal signifying one of the signals, based on the signal metric. The receiver further comprises a multiplexer configured to output one of the signals, based on the selection signal. In another embodiment, a wireless networking receiver comprises signal receiving means, carrier sensing means for calculating and selecting a signal based on a signal metric, and multiplexer means to output the signal. A related method is also disclosed. Other embodiments are provided, and each of the embodiments described herein can be used alone or in combination with one another.

Claims

1. A wireless networking receiver, comprising:

a demultiplexer configured to;

receive a plurality of radio frequency (RF) signals; and

send each of the plurality of RF signals to one of a high rate datapath and a low rate datapath;

a carrier sense circuit configured to calculate a signal metric for each of the plurality of received RF signals on the high rate datapath and generate, based on the signal metric, a selection signal signifying one of the plurality of received RF signals on the high rate datapath;

a first multiplexer configured to;

receive the selection signal and the plurality of received RF signals on the high rate datapath; and

output the one of the plurality of received RF signals from the high rate datapath based on the selection signal; and

a second multiplexer in communication with the high rate datapath and the low rate datapath, the second multiplexer configured to;

receive the one of the plurality of received RF signals from the high rate datapath and at least one RF signal from the low rate datapath; and

send the one of the plurality of received RF signals from the high rate data path and the at least one RF signal from the low rate datapath to a downstream path.

2. The receiver of claim 1, wherein the signal metric comprises a signal quality;

and the carrier sense circuit is further configured to generate the selection signal signifying the one of the plurality of received RF signals with a highest signal quality.

3. The receiver of claim 2, wherein the signal metric comprises a signal quality that is based on a measurement of a peak magnitude and a delay dispersion.

4. The receiver of claim 2, wherein the highest signal quality comprises a highest ratio of a peak magnitude over delay dispersions.

5. The receiver of claim 1, wherein the signal metric comprises a peak magnitude;

and the carrier sense circuit is further configured to generate the selection signal signifying the one of the plurality of received RF signals with a highest peak magnitude.

6. The receiver of claim 1, wherein the carrier sense circuit comprises:

a signal metric calculator configured to calculate the signal metric for each of the plurality of received RF signals sent to the high rate datapath; and

a comparator configured to compare the signal metric for each of the plurality of received RF signals sent to the high rate datapath and generate, based on the comparison, the selection signal signifying the one of the plurality of received RF signals sent to the high rate datapath.

7. The receiver of claim 1, wherein the plurality of RF signals comprise signals conforming to IEEE 802.11b.

8. The receiver of claim 7, further comprising a signal detection circuit configured to detect from the plurality of received RF signals a signal conforming to the IEEE 802.11b standard and generate a detection signal denoting a presence of the signal conforming to the IEEE 802.11b standard in the plurality of received RF signals.

9. The receiver of claim 8, wherein the selection signal is latched when the detection signal is active.

10. The receiver of claim 1, wherein the plurality of RF signals comprise signals modulated using a complementary code keying scheme.

11. The receiver of claim 1, wherein the plurality of RF signals comprise signals modulated using a phase shift keying scheme.

12. The receiver of claim 1, wherein the plurality of RF signals comprise signals modulated using a differential phase shift keying scheme.

13. The receiver of claim 1, wherein each of the plurality of RF signals comprises an RF signal in a 2.4 GHz frequency band operating at a data rate of approximately 1, 2, 5.5, or 11 megabits per second.

14. The receiver of claim 1, wherein the wireless networking receiver is configured to conform to IEEE 802.11n.

15. A method of selecting a radio frequency signal, comprising:

receiving, with a demultiplexer, a plurality of RF signals;

sending, with the demultiplexer, each of the plurality of RF signals to one of a high rate data path and a low rate data path;

calculating a signal metric for each of the plurality of received RF signals on the high rate datapath;

generating, based on the signal metric, a selection signal signifying one of the plurality of received RF signals on the high rate datapath;

outputting, from a first multiplexer to a second multiplexer, the one of the plurality of received RF signals on the high rate datapath based on the selection signal; and

outputting, with the second multiplexer, the one of the plurality received RF signals from the high rate datapath and at least one signal from the low rate datapath.

16. The method of claim 15, wherein the signal metric comprises a signal quality;

and further comprising generating the selection signal signifying the one of the plurality of received RF signals with a highest signal quality.

17. The method of claim 16, wherein the highest signal quality comprises a highest ratio of a peak magnitude over delay dispersions.

18. The method of claim 15, wherein the signal metric comprises a signal quality based on a measurement of a peak magnitude and a delay dispersion.

19. The method of claim 15, wherein the signal metric comprises a peak magnitude;

and further comprising generating the selection signal signifying the one of the plurality of received RF signals with a highest peak magnitude.

20. The method of claim 15, wherein generating the selection signal comprises:

comparing the signal metric for each of the plurality of received RF signals on the high rate datapath; and

generating the selection signal signifying one of the received RF signals on the high rate datapath, based on the comparison.

21. The method of claim 15, wherein the plurality of RF signals comprise signals conforming to IEEE 802.11b.

22. The method of claim 21, further comprising:

detecting from the plurality of received RF signals a signal conforming to the IEEE 802.11b standard; and

generating a detection signal denoting a presence of the signal conforming to the IEEE 802.11b standard in the plurality of received RF signals.

23. The method of claim 22, further comprising latching the selection signal when the detection signal is generated.

24. The method of claim 15, wherein the plurality of RF signals comprise signals modulated using a complementary code keying scheme.

25. The method of claim 15, wherein the plurality of RF signals comprise signals modulated using a phase shift keying scheme.

26. The method of claim 15, wherein the plurality of RF signals comprise signals modulated using a differential phase shift keying scheme.

27. The method of claim 15, wherein each of the plurality of RF signals comprises an RF signal in a 2.4 GHz frequency band operating at a data rate of approximately 1, 2, 5.5, or 11 megabits per second.

28. The receiver of claim 15, wherein the plurality of RF signals comprise signals conforming to IEEE 802.11n.