Transmit power control within a wireless transmitter

• US 7,245,880 B1
• Filed: 08/31/2000
• Issued: 07/17/2007
• Est. Priority Date: 08/31/2000
• Status: Expired due to Fees

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Jacobsen, Eric A.
• Primary Examiner(s): D AGOSTA, STEPHEN M
• Application Number:
  US09/652,773
• Time in Patent Office: 2,511 Days
• Field of Search: 455/69, 455/13.4, 455/522, 455/562, 455/452.2, 370/318
• US Class Current: 455/69
• CPC Class Codes: H04W 52/146 Uplink power control
• CPC Class Codes: H04W 52/223 predicting future states of the transmission
• CPC Class Codes: H04W 52/367 Power values between minimum and maximum limits, e.g. dynamic range
• CPC Class Codes: H04W 52/42 in systems with time, space, frequency or polarisation diversity

Abstract

A wireless transmitter system for use in maintaining a wireless link with a remote transceiver includes a beamforming transmit antenna structure and a power control unit for controlling transmit power levels. The system determines the direction of the remote transceiver and then generates a transmit antenna beam in that direction. The power control unit then determines the antenna gain of the generated beam and uses the antenna gain information to adjust the transmit power level of the system so that it does not exceed government mandated limits. In one embodiment, the average transmit duty cycle of the system is also used to adjust transmit power. The system is capable of achieving a maximum transmit power without exceeding applicable power limits.

Claims

1. A system for use in wirelessly transmitting a communication signal to a remote transceiver, said system comprising:

an array of transmit antenna elements arranged in a predetermined pattern;

a direction determination unit to determine a direction of the remote transceiver;

a transmit beamformer coupled to said array of antenna elements to generate a transmit beam in the direction of the remote transceiver;

a power control unit to determine an antenna gain related parameter associated with said transmit beam generated by said transmit beamformer and to adjust a transmit power level of said system based on said antenna gain related parameter; and

a duty cycle unit, coupled to said power control unit, to determine an average transmit duty cycle of said system over a predetermined time period and to deliver said average transmit duty cycle information to said power control unit, wherein said power control unit uses said average transmit duty cycle information to adjust the transmit power level of said system.

2. The system claimed in claim 1, wherein:

said power control unit adjusts said transmit power level of said system to comply with mandated transmit power limits.

3. The system claimed in claim 1, wherein:

said array of transmit antenna elements, said direction determination unit, and said transmit beamformer are each part of an adaptive antenna arrangement.

4. The system claimed in claim 1, further comprising:

an array of receive antenna elements that are arranged in a predetermined pattern for use in receiving a communication signal from the remote transceiver, wherein said direction determination unit includes means for analyzing signal portions received by individual antenna elements within said array of receive elements to determine the direction of the remote transceiver.

5. The system claimed in claim 1, wherein:

said transmit beam generated by said transmit beamformer is approximately centered in the direction of the remote transceiver determined by said direction determination unit.

6. The system claimed in claim 1, further comprising:

an input/output interface to couple said system to a data processing device.

7. The system claimed in claim 6, wherein:

said input/output interface includes a serial data port.

8. The system claimed in claim 6, wherein:

said input/output interface includes a universal serial bus (USB) port.

9. The system claimed in claim 6, wherein:

said input/output interface includes plug-and-play capability.

10. The system claimed in claim 1, wherein:

said array of transmit antenna elements, said direction determination unit, said transmit beamformer, and said power control unit are each mounted on a common support structure.

11. The system claimed in claim 10, wherein:

said common support structure is adapted for desktop placement.

12. The system claimed in claim 1, comprising:

at least one variable gain amplifier to amplify a transmit signal before it is delivered to said array of transmit antenna elements during a transmit operation, wherein said power control unit controls the gain of said at least one variable gain amplifier to adjust the transmit power level of said system.

13. A system for use in wirelessly transmitting a communication signal to a remote transceiver, said system comprising:

an array of transmit antenna elements arranged in a predetermined pattern;

a direction determination unit to determine a direction of the remote transceiver;

a transmit beamformer coupled to said array of antenna elements to generate a transmit beam in the direction of the remote transceiver;

a power control unit to determine an antenna gain related parameter associated with said transmit beam generated by said transmit beamformer and to adjust a transmit power level of said system based on said antenna gain related parameter, and

wherein said transmit beamformer includes a variable delay unit for each of said antenna elements within said array of transmit antenna elements and a controller to determine a delay setting for each variable delay unit based upon the direction of the remote transceiver determined by said direction determination unit.

14. The system claimed in claim 13, wherein:

said power control unit includes a controller to calculate said antenna gain related parameter based upon delay settings of said transmit beamformer.

15. A method for use in wirelessly transmitting a communication signal to a remote location, said method comprising:

determining a direction of said remote location;

generating a transmit antenna beam in the direction of said remote location using phased array principles from an array of transmit antenna elements;

determining a parameter related to an antenna gain associated with said transmit antenna beam;

using said antenna gain related parameter to adjust a power level of a transmit signal to be transmitted to said remote location via said transmit antenna beam;

determining a delay setting for a variable delay unit for each of said antenna elements within said array based upon the direction of said remote location;

determining an average transmit duty cycle associated with transmissions to said remote location; and

using said average transmit duty cycle to adjust the power level of said transmit signal.

16. The method claimed in claim 15, wherein:

determining a direction of said remote location includes receiving an RF signal from said remote location and analyzing said RF signal to determine the direction of said remote location.

17. The method claimed in claim 15, wherein:

determining a direction, generating a transmit antenna beam, determining a parameter related to an antenna gain, and using said antenna gain related parameter are performed from a single indoor location.

18. The method claimed in claim 15, wherein:

using said antenna gain related parameter includes adjusting the power level of said transmit signal in a manner that complies with mandated transmit power limits.

19. The method claimed in claim 18, wherein:

using said antenna gain related parameter includes adjusting the power level of said transmit signal to maximize said power level while not exceeding said mandated transmit power limits.

20. The method claimed in claim 15, further comprising calculating said antenna gain related parameter based upon said delay settings.

21. A communication system for use in communicating with a remote communication entity, comprising:

an array of antenna elements arranged in a predetermined configuration;

an adjustable beamformer coupled to said array of antenna elements to generate a transmit beam in a predetermined direction in response to a control signal, said adjustable beamformer being capable of generating a beam in any of a plurality of different directions;

a power control unit to adjust a power level of a transmit signal to be transmitted by said array of antenna elements based on at least one parameter associated with said transmit beam generated by said adjustable beamformer; and

a duty cycle determination unit to determine an average transmit duty cycle of said system over a predetermined time period, wherein said power control unit adjusts the power level of the transmit signal to be transmitted by said array of antenna elements based on said average transmit duty cycle.

22. The communication system claimed in claim 21, wherein:

said at least one parameter associated with said transmit beam includes an antenna gain related parameter.

23. The communication system claimed in claim 21, wherein:

said adjustable beamformer generates the transmit beam in the predetermined direction using conventional phased array techniques.

24. The communication system claimed in claim 21, wherein:

said adjustable beamformer is part of an adaptive antenna arrangement.

25. The communication system claimed in claim 21, wherein:

said power control unit adjusts the power level of the transmit signal so that a maximum allowed power level is not exceeded.

26. A communication system for use in communicating with a remote communication entity, comprising:

an array of dipole antenna elements arranged in a predetermined configuration;

an adjustable beamformer coupled to said array of dipole antenna elements to generate a transmit beam in a predetermined direction in response to a control signal, said adjustable beamformer being capable of generating a beam in any of a plurality of different directions;

a power control unit to adjust a power level of a transmit signal to be transmitted by said array of dipole antenna elements based on at least one parameter associated with said transmit beam generated by said adjustable beamformer; and

a duty cycle determination unit to determine an average transmit duty cycle of said system over a predetermined time period, wherein said power control unit adjusts the power level of the transmit signal to be transmitted by said array of dipole antenna elements based on said average transmit duty cycle.

27. The communication system claimed in claim 26, wherein:

said at least one parameter associated with said transmit beam includes an antenna gain related parameter.

28. The communication system claimed in claim 26, wherein:

said adjustable beamformer generates the transmit beam in the predetermined direction using conventional phased array techniques.

29. The communication system claimed in claim 26, wherein:

said adjustable beamformer is part of an adaptive antenna arrangement.

30. The communication system claimed in claim 26, wherein:

said power control unit adjusts the power level of the transmit signal so that a maximum allowed power level is not exceeded.