Power efficient signal acquisition with multiple receive antennas

• US 7,349,720 B2
• Filed: 09/30/2004
• Issued: 03/25/2008
• Est. Priority Date: 09/30/2004
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Intel Corporation
• Inventors: Sandhu, Sumeet
• Primary Examiner(s): VO, NGUYEN THANH
• Application Number:
  US10/955,933
• Publication Number:
  US 20060068854A1
• Time in Patent Office: 1,272 Days
• Field of Search: 455/434, 455/515, 455/550.1, 455/562.1, 455132-134, 455/226.1, 455/226.2, 455/272, 455/277.1, 455/277.2, 455/574, 370/445
• US Class Current: 455/562.1
• CPC Class Codes: H04B 7/0874 using subgroups of receive antennas
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

In a wireless device having multiple receive antennas, wireless medium sensing operations are performed using a reduced number of receive antennas. Receive chains associated with unused receive antennas are deactivated to reduce power consumption within the device.

Claims

1. An apparatus comprising:

a plurality of analog receive chains to process signals received from a wireless medium; and

a controller to activate M receive chains within said plurality of analog receive chains during data receive operations and less than M receive chains within said plurality of analog receive chains during medium sensing operations, wherein M is a positive integer greater than 1 and receive chains that are not used during a medium sensing operation are deactivated during said medium sensing operation to conserve energy.

2. The apparatus of claim 1, wherein:

said controller to activate only one of said receive chains within said plurality of analog receive chains during medium sensing operations.

3. The apparatus of claim 1, wherein:

said controller to activate multiple receive chains within said plurality of analog receive chains during medium sensing operations.

4. The apparatus of claim 1, wherein:

said controller to select one or more receive chains from said plurality of analog receive chains to use during a medium sensing operation based on a predetermined criterion.

5. The apparatus of claim 1, wherein:

said controller to select one or more receive chains within said plurality of analog receive chains to use during medium sensing operations based on information from a previously received data packet.

6. The apparatus of claim 1, wherein:

said controller to select one or more receive chains within said plurality of analog receive chains to use during medium sensing operations using a round robin approach.

7. The apparatus of claim 1, wherein:

said apparatus is configured in accordance with the IEEE 802.11 wireless networking standard; and

said medium sensing operations include clear channel assessment (CCA) operations.

8. The apparatus of claim 1, wherein:

said plurality of analog receive chains includes M receive chains.

9. A method comprising:

providing a wireless device having multiple receive antennas, each of said multiple receive antennas having a corresponding receive chain, said wireless device to perform both data receive operations and medium sensing operations;

activating M receive chains within said wireless device during data receive operations, wherein M is a positive integer greater than 1; and

activating less than M receive chains within said wireless device during medium sensing operations to conserve energy.

10. The method of claim 9, wherein:

said less than M receive chains includes only one receive chain.

11. The method of claim 9, wherein:

said less than M receive chains includes multiple receive chains.

12. The method of claim 9, wherein:

said wireless device includes a total of M receive chains.

13. The method of claim 9, wherein:

said wireless device is configured in accordance with the IEEE 802.11 wireless networking standard; and

said medium sensing operations include clear channel assessment (CCA) operations.

14. The method of claim 9, further comprising:

determining which receive chains within said wireless device to activate during a medium sensing operation based on a predetermined criterion.

15. The method of claim 9, further comprising:

determining which receive chains within said wireless device to activate during a medium sensing operation based on information from a previously received data packet.

16. The method of claim 9, further comprising:

determining which receive chains within said wireless device to activate during a medium sensing operation based on a round robin sequence.

17. An apparatus comprising:

a plurality of antennas including at least one dipole antenna;

a plurality of receive chains to process signals received from a wireless medium, each receive chain in said plurality of receive chains being coupled to an antenna in said plurality of antennas; and

a controller to activate M receive chains within said plurality of receive chains during data receive operations and less than M receive chains within said plurality of receive chains during medium sensing operations, wherein M is a positive integer greater than 1 and receive chains that are not used during a medium sensing operation are deactivated during said medium sensing operation to conserve energy.

18. The apparatus of claim 17, wherein:

said controller to select one or more receive chains from said plurality of receive chains to use during a medium sensing operation based on a predetermined criterion.

19. The apparatus of claim 17, wherein:

said apparatus is configured in accordance with the IEEE 802.11 wireless networking standard; and

said medium sensing operations include clear channel assessment (CCA) operations.

20. An article comprising a computer readable storage medium having computer executable instructions stored thereon that, when executed by a computing platform, operate to:

activate M receive chains within a wireless device during data receive operations, wherein M is a positive integer greater than 1, wherein said wireless device includes multiple receive antennas, each of said multiple receive antennas having a corresponding receive chain; and

activate less than M receive chains within said wireless device during medium sensing operations to conserve energy.

21. The article of claim 20, wherein:

said wireless device is configured in accordance with the IEEE 802.11 wireless networking standard; and

said medium sensing operations include clear channel assessment (CCA) operations.

22. The article of claim 20, wherein said instructions further operate to:

determine which receive chains within said wireless device to activate during a medium sensing operation based on a predetermined criterion.