Wireless communication with interference mitigation

Patent metadata

Field	Value
Publication number	US-9667335-B2
Application number	US-201514984553-A
Country	US
Kind code	B2
Filing date	Dec 30, 2015
Priority date	Sep 12, 2014
Publication date	May 30, 2017
Grant date	May 30, 2017

Abstract

In one implementation, a wireless communication terminal includes a primary antenna array and a first controller configured to steer a main beam of the primary antenna array in a desired direction. The wireless communication terminal also includes an auxiliary antenna array and a second controller configured to control complex weights to be applied by at least some antenna elements of the auxiliary antenna array to corresponding variants of a second signal received by the at least some auxiliary antenna elements. Furthermore, the wireless communication terminal includes at least one signal combiner configured to combine variants of the second signal received from auxiliary antenna elements into an interfering signal that models interference from a co-located wireless communication terminal and subtract the interfering signal from variants of the first signal received from antenna elements of the principal antenna array to produce an interference mitigated signal.

First claim

What is claimed is:

1. A wireless communication terminal comprising:
a primary antenna array including a first number of primary antenna elements;
a first controller configured to steer a main beam of the primary antenna array in a desired direction;
an auxiliary antenna array including a second number of auxiliary antenna elements;
a second controller configured to control, based on the desired direction of the main beam of the primary antenna array, complex weights to be applied by at least some of the auxiliary antenna elements; and
at least one signal combiner configured to:
combine signals received from auxiliary antenna elements into an interfering signal, the interfering signal to model interference from a co-located wireless communication terminal received in a side lobe of the primary antenna array when the main beam is in the desired direction, and
subtract the interfering signal from signals received from primary antenna elements to produce an interference mitigated signal.

2. The wireless communication terminal of claim 1 , further comprising a power receiver to measure power of the interference mitigated signal, wherein the second controller is configured to control the complex weights to be applied to reduce the power of the interference mitigated signal measured by the power receiver.

3. The wireless communication terminal of claim 1 , further comprising:
an oscillator configured to convert the interference mitigated signal to an intermediate frequency, wherein the interfering signal is subtracted from the signals received from the primary antenna elements before the interference mitigated signal is converted to the intermediate frequency.

4. The wireless communication terminal of claim 1 , wherein:
the first controller is configured to steer the main beam of the primary antenna array in a plurality of predetermined directions; and
the second controller is further configured to control the complex weights to be applied by the at least some of the auxiliary antenna elements for each predetermined direction in which the first controller is configured to steer the main beam of the primary antenna array.

5. The wireless communication terminal of claim 1 , wherein the at least one signal combiner includes:
a first signal combiner configured to combine the signals received from the auxiliary antenna elements into the interfering signal; and
a second signal combiner that is different from the first signal combiner configured to subtract the interfering signal from the signals received from the primary antenna elements to produce the interference mitigated signal.

6. The wireless communication terminal of claim 1 , wherein the at least one signal combiner includes:
a first signal combiner to combine signals received from primary antenna elements into a main signal;
a second signal combiner that is different from the first signal combiner configured to combine signals received from the auxiliary antenna elements into the interfering signal; and
a third signal combiner that is different from the first and second signal combiners configured to subtract the interfering signal from the main signal to produce the interference mitigated signal.

7. The wireless communication terminal of claim 1 , wherein the at least one signal combiner is configured to:
combine signals received from all of the auxiliary antenna elements into the interfering signal; and
subtract the interfering signal from signals received from all of the primary antenna elements to produce an interference mitigated signal.

8. The wireless communication terminal of claim 1 , wherein:
the first controller is configured to:
steer the main beam of the primary antenna in a new desired direction, and
communicate an indication of the new desired direction to the second controller; and

the second controller is configured to:
receive the indication of the new desired direction, and
change the complex weights to be applied by at least some of the auxiliary antenna elements based on the new desired direction.

9. The wireless communication terminal of claim 1 , wherein:
each of at least some of the primary antenna elements is configured to apply a complex weight to a signal received by the primary antenna element; and
the first controller is configured to steer the main beam of the primary antenna array in a desired direction by controlling complex weights applied by the at least some primary antenna elements to the signals received by the at least some primary antenna elements.

10. The wireless communication terminal of claim 9 , wherein each of at least some of the primary antenna elements include:
a power amplifier to amplify signals to be transmitted by the primary antenna element; and
a low noise amplifier to amplify signals received by the primary antenna element.

11. The wireless communication terminal of claim 1 , wherein the first number of primary antenna elements is greater than the second number of auxiliary antenna elements.

12. The wireless communication terminal of claim 1 , wherein the second controller is configured to control, based on the desired direction of the main beam of the primary antenna array, a complex weight to be applied by each auxiliary antenna element.

13. The wireless communication terminal of claim 1 , wherein:
a desired signal is transmitted by two or more satellites orbiting the earth; and
the first controller is configured to:
steer the main beam of the primary antenna array in a desired direction to receive the desired signal from a first one of the satellites, and
change the direction of the main beam of the primary antenna array to a new desired direction to receive the desired signal from a second one of the satellites based on a determination that the main beam of the primary antenna array will be subjected to interference from a co-located satellite terminal when steered in the desired direction to receive the desired signal from the first satellite.

14. A method for processing a desired signal by a wireless communication terminal, comprising:
receiving a main signal with a primary antenna array, the main signal including noise from a proximally located wireless communication terminal received in one or more side lobes of the primary antenna array;
setting complex weights to be applied by individual antenna elements of the auxiliary antenna array based on a direction of a main beam of the primary antenna array;
applying the complex weights to shift signals received by the individual antenna elements;
combining the shifted signals received by the individual antenna elements into an interfering signal to model the noise from the proximally located wireless communication terminal received in the one or more side lobes of the primary antenna array; and
subtracting the interfering signal from the main signal to produce an interference mitigated signal.

15. The method of claim 14 , wherein setting the complex weights comprises:
measuring power in the interference mitigated signal; and
setting the complex weights to reduce the power measured in the interference signal.

16. The method of claim 14 , further comprising steering the main beam of the primary antenna array to a particular one of a plurality of predetermined directions, wherein setting the complex weights includes setting the complex weights based on the main beam of the primary antenna having been steered in the particular direction.

17. The method of claim 14 , wherein receiving a main signal with a primary antenna array comprises:
receiving variants of the mai

Assignees

• Iridium Satellite Llc

Inventors

• Bull Jeffrey Francis

Classifications

• H04B1/44

  Transmit/receive switching · CPC title

• H01Q3/267

  Phased-array testing or checking devices · CPC title

• H04W52/52

  using AGC [Automatic Gain Control] circuits or amplifiers · CPC title

• H04W16/28

  using beam steering · CPC title

• H01Q3/2605

  Array of radiating elements provided with a feedback control over the element weights, e.g. adaptive arrays · CPC title