Method and System for Power Headroom Reporting in the Presence of Multiple Transmit Antennas

• US 20120213149A1
• Filed: 03/31/2011
• Published: 08/23/2012
• Est. Priority Date: 09/21/2010
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Chakraborty, Soumen, Ranjan, Rishi, Stauffer, Erik, Rath, Kamlesh, Airy, Manish
• Granted Patent: US 9,173,178 B2
• Time in Patent Office: Days
• US Class Current: 370/328
• CPC Class Codes: H04W 52/146 Uplink power control
• CPC Class Codes: H04W 52/365 Power headroom reporting
• CPC Class Codes: H04W 52/42 in systems with time, space, frequency or polarisation diversity

Abstract

A method and system are provided in which a mobile device may be operable for long term evolution (LTE) communication or some other wireless technology via two or more transmit antennas. The device may comprise a power amplifier for each transmit antenna with substantially similar maximum power being provided by both amplifiers. A power headroom value may be determined in the device based on path loss values between the transmit antennas and a base station and the maximum transmit power for each transmit antenna. Transmission via one of the transmit antennas may occur concurrently with transmission via another of the transmit antennas. The device may generate an indication of the determined power headroom value for communication to the base station. The power headroom value may be reported periodically or in response to a change in the power received at the base station.

Claims

1. A method, comprising:

in a mobile device that is operable to wirelessly communicate with a base station via a plurality of transmit antennas;

determining a power headroom value based on a path loss value from the base station for each of the plurality of transmit antennas and based on a maximum transmit power associated with each of the plurality of transmit antennas; and

generating an indication of the determined power headroom value for communication to the base station.

2. The method of claim 1, wherein the mobile device comprises a power amplifier for each of the plurality of transmit antennas.

3. The method of claim 1, wherein the maximum transmit power associated with each of the plurality of transmit antennas is substantially the same.

4. The method of claim 1, wherein the maximum transmit power associated with one or more of the plurality of transmit antennas is different from the maximum transmit power associated with the remaining transmit antennas from the plurality of transmit antennas.

5. The method of claim 1, wherein a maximum transmit total power associated with the mobile device is different from a sum of the maximum transmit powers associated with the plurality of transmit antennas.

6. The method of claim 1, wherein the mobile device is operable to wirelessly communicate with the base station utilizing long term evolution (LTE) communication.

7. The method of claim 1, comprising determining the power headroom value utilizing the following expression:

8. The method of claim 1, comprising:

reporting to the base station an update to the power headroom value in response to changes in one or more parameters associated with the reception of signals at the base station; and

generating an indication of the updated power headroom value for communication to the base station.

9. The method of claim 1, wherein the base station with which the mobile device wirelessly communicates comprises more than one receive antenna.

10. A method, comprising:

in a base station comprising one or more receive antennas and that is operable to wirelessly communicate with a mobile device comprising a plurality of transmit antennas;

receiving a power headroom value from the mobile device, wherein the power headroom value is generated by the mobile device based on a path loss value from the base station for each of the plurality of transmit antennas and based on a maximum transmit power associated with each of the plurality of transmit antennas; and

processing the received power headroom value to adjust one or more link parameters.

11. A system, comprising:

one or more processors and/or circuits for use in a mobile device that is operable to wirelessly communicate with a base station utilizing a plurality of antennas, the one or more processors and/or circuits being operable to;

determine a power headroom value based on a path loss value from the base station for each of the plurality of transmit antennas and based on a maximum transmit power associated with each of the plurality of transmit antennas; and

generate an indication of the determined power headroom value for communication to the base station.

12. The system of claim 11, wherein the one or more processors and/or circuits comprise a power amplifier for each of the plurality of transmit antennas.

13. The system of claim 11, wherein the maximum transmit power associated with each of the plurality of transmit antennas is substantially the same.

14. The system of claim 11, wherein the maximum transmit power associated with one or more of the plurality of transmit antennas is different from the maximum transmit power associated with the remaining transmit antennas from the plurality of transmit antennas.

15. The system of claim 11, wherein a maximum transmit total power associated with the mobile device is different from a sum of the maximum transmit powers associated with the plurality of transmit antennas.

16. The system of claim 11, wherein the mobile device is operable to wirelessly communicate with the base station utilizing LTE communication.

17. The system of claim 11, wherein the one or more processors and/or circuits are operable to determine the power headroom value utilizing the following expression:

18. The system of claim 11, wherein the one or more processors and/or circuits are operable to:

report to the base station an update to the power headroom value in response to changes in one or more parameters associated with the reception of signals at the base station; and

generate an indication of the updated power headroom value for communication to the base station.

19. The system of claim 11, wherein the base station with which the mobile device wirelessly communicates comprises more than one receive antenna.

20. A system, comprising:

one or more processors and/or circuits for use in a base station comprising one or more receive antennas and that is operable to wirelessly communicate with a mobile device comprising a plurality of transmit antennas, the one or more processors and/or circuits being operable to;

receive a power headroom value from the mobile device, wherein the power headroom value is generated by the mobile device based on a path loss value from the base station for each of the plurality of transmit antennas and based on a maximum transmit power associated with each of the plurality of transmit antennas; and

process the received power headroom value to adjust one or more link parameters.