Wireless communication terminal

• US 9,882,279 B2
• Filed: 09/24/2014
• Issued: 01/30/2018
• Est. Priority Date: 09/24/2014
• Status: Active Grant

• Current Assignee: Iridium Satellite Llc (Iridium Communications, Incorporated)
• Original Assignee: Iridium Satellite Llc (Iridium Communications, Incorporated)
• Inventors: Bull, Jeffrey Francis, Fuchs, Alden Joe, Woloszynski, Charles Howard
• Primary Examiner(s): Nguyen, Chuong P
• Application Number:
  US14/494,797
• Publication Number:
  US 20160087339A1
• Time in Patent Office: 1,224 Days
• Field of Search: 342367, 342354, 342368, 342371, 342372
• CPC Class Codes: H01Q 3/22 varying the orientation in accordance with variation of frequency of radiated wave
• CPC Class Codes: H01Q 3/26 varying the relative phase or relative amplitude of energisation between two or more active radiating elements; varying the distribution of energy across a radiating aperture H01Q3/12, H01Q3/22, H01Q3/24 take precedence
• CPC Class Codes: H01Q 3/34 by electrical means active lenses or reflecting arrays H01Q3/46
• CPC Class Codes: H01Q 3/36 with variable phase-shifters
• CPC Class Codes: H04B 17/18 Monitoring during normal operation
• CPC Class Codes: H04B 7/0617 for beam forming
• CPC Class Codes: H04W 16/28 using beam steering

Abstract

In one implementation, an antenna array has a plurality of antenna element, each of which is configured to apply a phase shift to a signal. A beam steering controller is configured to steer a main beam of the antenna by controlling the phase shifts applied by the antenna elements. In addition, the beam steering controller also is configured to detect a failure of an antenna element and, in response to detecting the failure, disable the failed antenna element and modify the phase shifts applied by remaining ones of the antenna elements.

Claims

1. A wireless communications terminal, comprising:

an antenna array having a plurality of antenna elements, each of which is configured to apply a phase shift to a signal transmitted by the antenna element; and

a beam steering controller configured to;

steer a main beam of the antenna by controlling the phase shifts applied by the antenna elements,

detect a failure of an antenna element, and

in response to detecting the failure of the antenna element;

disable the failed antenna element,

modify the phase shifts applied by remaining ones of the antenna elements;

wherein the wireless communication terminal is configured to;

modulate signals transmitted by the antenna using at least one of a first signal constellation and a second signal constellation; and

switch from using the first signal constellation to modulate signals prior to detecting the failure of the failed antenna element to using the second signal constellation to modulate signals in response to detecting the failure of the failed antenna element.

2. The wireless communications terminal of claim 1, further comprising a memory storing a beam pointing data structure storing values indicative of different phase shifts to be applied by corresponding antenna elements to steer the main beam of the antenna in each of multiple different predetermined directions, wherein the beam steering controller is configured to control the phase shifts applied by the antenna elements by reading values indicative of phase shifts to be applied from the beam pointing data structure.

3. The wireless communications terminal of claim 2, wherein:

the memory further stores an alternative beam pointing data structure storing values indicative of different phase shifts to be applied by corresponding remaining antenna elements to steer the main beam of the antenna in at least some of the multiple predetermined directions; and

the beam steering controller is configured to modify the phase shifts applied by the remaining antenna elements by reading values indicative of phase shifts to be applied from the alternative beam pointing table.

4. The wireless communications terminal of claim 1, wherein the beam steering controller is configured to disable the failed antenna element by applying a predetermined impedance to the failed antenna element.

5. The wireless communications terminal of claim 1, wherein each antenna element includes a power amplifier configured to amplify the signal transmitted by the antenna element.

6. The wireless communications terminal of claim 5, wherein the beam steering controller is configured to detect the failure of the antenna element by detecting the failure of the power amplifier in the failed antenna element.

7. The wireless communications terminal of claim 1, wherein each antenna element is further configured to apply a phase shift to a signal received by the antenna element.

8. The wireless communications terminal of claim 1, wherein the second signal constellation is less sensitive to noise than the first signal constellation.

9. A method of operating a phased array antenna that includes multiple antenna elements, the method comprising:

controlling phase shifts applied by individual ones of the antenna elements to steer a main beam of the antenna in a direction;

determining that one of the antenna elements has failed; and

in response to determining that the antenna element has failed;

disabling the failed antenna element, and

modifying the phase shifts applied by remaining ones of the antenna elements to steer the main beam of the antenna effectively in the same direction; and

further comprising;

using a first signal constellation to modulate signals transmitted by the antenna prior to determining that the antenna element has failed; and

in response to determining that the antenna element has failed, using a second signal constellation that is different from the first signal constellation to modulate signals transmitted by the antenna.

10. The method of claim 9, wherein controlling phase shifts applied by individual ones of the antenna elements to steer a main beam of the antenna in a direction includes reading the phase shifts to be applied to the individual antenna elements from a first beam pointing table.

11. The method of claim 10, wherein modifying the phase shifts applied by remaining ones of the antenna elements to steer the main beam of the antenna effectively in the same direction includes reading the modified offsets to be applied by remaining ones of the antenna elements from a second beam pointing table that is different from the first beam pointing table.

12. The method of claim 9, wherein disabling the failed antenna element includes applying a predetermined impedance to the failed antenna element.

13. The method of claim 9, further comprising:

amplifying signals transmitted by individual ones of the antenna elements using power amplifiers incorporated within the individual antenna elements.

14. The method of claim 13, wherein determining that the antenna element has failed includes determining that the power amplifier included in the failed antenna element has failed.

15. The method of claim 9, wherein using a second signal constellation that is different from the first signal constellation to modulate signals transmitted by the antenna includes using a second signal constellation that is less sensitive to noise than the first signal constellation to modulate signals transmitted by the antenna.

16. A wireless communication terminal, comprising:

a phased array antenna having multiple antenna elements;

memory storing multiple different beam pointing data structures, each beam pointing data structure;

corresponding to a particular combination of enabled and disabled antenna elements of the antenna, and

storing values representing phase shifts to be applied by individual ones of the enabled antenna elements for the particular combination to steer the main beam of the antenna in a number of different predetermined directions; and

a beam steering controller configured to;

determine a current combination of enabled and disabled antenna elements,

select a beam pointing data structure from among the multiple different beam pointing data structures that corresponds to the current combination of enabled and disabled antenna elements, and

control phase shifts applied by the currently enabled antenna elements to steer the main beam of the antenna using phase shifts represented in the selected beam pointing data structure; and

wherein;

each antenna element is configured to operate in at least one of a transmit mode for transmitting a signal and a receive mode for receiving a signal;

each antenna element includes a power amplifier for amplifying a signal transmitted by the antenna element when the antenna element is operating in the transmit mode;

the wireless communication terminal is configured to;

operate in at least one of a transmitting mode for transmitting signals from the antenna and a receiving mode for receiving signals with the antenna,

control individual antenna elements to operate in their transmit modes when the wireless communication terminal is operating in the transmitting mode,

control individual antenna elements to operate in their receive modes when the wireless communication terminal is operating in the receiving mode,

detect that a power amplifier of an antenna element has failed, and

disable an antenna element from operating in the transmit mode as a consequence of detecting that the power amplifier of the antenna element has failed;

the beam steering controller is configured to determine a current combination of enabled and disabled antenna elements by detecting a first current combination of enabled and disabled antenna elements for operating in the transmit mode when the wireless communication terminal is operating in the transmitting mode and a second combination of enabled and disabled antenna elements for operating in the receive mode when the wireless communication terminal is operating in the receiving mode; and

the beam steering controller is configured to select a beam pointing data structure from among the multiple different beam pointing data structures that corresponds to the current combination of enabled and disabled antenna elements by selecting a transmitting beam pointing data structure that corresponds to the first current combination of enabled and disabled antenna elements when the wireless communication terminal is operating in the transmitting mode and by selecting a receiving beam pointing data structure that corresponds to the second current combination of enabled and disabled antenna elements when the wireless communication terminal is operating in the receiving mode.

17. The wireless communication terminal of claim 16, wherein the wireless communication terminal is configured to:

modulate signals transmitted by the antenna using multiple different modulation techniques, individual ones of the modulation techniques having different sensitivities to noise; and

select a particular one of the modulation techniques to use to modulate signals transmitted by the antenna based on the current combination of enabled and disabled antenna elements.

18. A wireless communications terminal, comprising:

an antenna array having a plurality of antenna elements, each of which is configured to apply a phase shift to a signal transmitted by the antenna element; and

a beam steering controller configured to;

steer a main beam of the antenna by controlling the phase shifts applied by the antenna elements,

detect a failure of an antenna element, and

in response to detecting the failure of the antenna element;

disable the failed antenna element, and

modify the phase shifts applied by remaining ones of the antenna elements;

wherein controlling phase shifts applied by individual ones of the antenna elements to steer a main beam of the antenna in a direction includes reading the phase shifts to be applied to the individual antenna elements from a first beam pointing table; and

wherein modifying the phase shifts applied by remaining ones of the antenna elements to steer the main beam of the antenna effectively in the same direction includes reading the modified offsets to be applied by remaining ones of the antenna elements from a second beam pointing table that is different from the first beam pointing table.

19. The wireless communications terminal of claim 18,

further comprising a memory storing a beam pointing data structure storing values indicative of different phase shifts to be applied by corresponding antenna elements to steer the main beam of the antenna in each of multiple different predetermined directions, wherein the beam steering controller is configured to control the phase shifts applied by the antenna elements by reading values indicative of phase shifts to be applied from the beam pointing data structure.

20. The wireless communications terminal of claim 19,

wherein:

the memory further stores an alternative beam pointing data structure storing values indicative of different phase shifts to be applied by corresponding remaining antenna elements to steer the main beam of the antenna in at least some of the multiple predetermined directions; and

the beam steering controller is configured to modify the phase shifts applied by the remaining antenna elements by reading values indicative of phase shifts to be applied from the alternative beam pointing table.

21. The wireless communications terminal of claim 18,

wherein the beam steering controller is configured to disable the failed antenna element by applying a predetermined impedance to the failed antenna element.

22. The wireless communications terminal of claim 18,

wherein each antenna element includes a power amplifier configured to amplify the signal transmitted by the antenna element;

and

wherein the beam steering controller is configured to detect the failure of the antenna element by detecting the failure of the power amplifier in the failed antenna element.

23. The wireless communications terminal of claim 18,

wherein the wireless communication terminal is configured to:

modulate signals transmitted by the antenna using at least one of a first signal constellation and a second signal constellation; and

switch from using the first signal constellation to modulate signals prior to detecting the failure of the failed antenna element to using the second signal constellation to modulate signals in response to detecting the failure of the failed antenna element.

24. The wireless communications terminal of claim 23,

wherein the second signal constellation is less sensitive to noise than the first signal constellation.

25. A method of operating a phased array antenna that includes multiple antenna elements, the method comprising:

controlling phase shifts applied by individual ones of the antenna elements to steer a main beam of the antenna in a direction;

determining that one of the antenna elements has failed; and

in response to determining that the antenna element has failed;

disabling the failed antenna element, and

modifying the phase shifts applied by remaining ones of the antenna elements to steer the main beam of the antenna effectively in the same direction,

wherein controlling phase shifts applied by individual ones of the antenna elements to steer a main beam of the antenna in a direction includes reading the phase shifts to be applied to the individual antenna elements from a first beam pointing table; and

wherein modifying the phase shifts applied by remaining ones of the antenna elements to steer the main beam of the antenna effectively in the same direction includes reading the modified offsets to be applied by remaining ones of the antenna elements from a second beam pointing table that is different from the first beam pointing table.

26. The method of operating a phased array antenna that includes multiple antenna elements of claim 25,

wherein disabling the failed antenna element includes applying a predetermined impedance to the failed antenna element.

27. The method of operating a phased array antenna that includes multiple antenna elements of claim 25,

further comprising:

amplifying signals transmitted by individual ones of the antenna elements using power amplifiers incorporated within the individual antenna elements; and

wherein determining that the antenna element has failed includes determining that the power amplifier included in the failed antenna element has failed.

28. The method of operating a phased array antenna that includes multiple antenna elements of claim 25,

further comprising:

using a first signal constellation to modulate signals transmitted by the antenna prior to determining that the antenna element has failed; and

in response to determining that the antenna element has failed, using a second signal constellation that is different from the first signal constellation to modulate signals transmitted by the antenna.

29. The method of operating a phased array antenna that includes multiple antenna elements of claim 28,

wherein using a second signal constellation that is different from the first signal constellation to modulate signals transmitted by the antenna includes using a second signal constellation that is less sensitive to noise than the first signal constellation to modulate signals transmitted by the antenna.