Apparatus and method for transmitting and receiving polarized signals

Patent metadata

Field	Value
Publication number	US-9628219-B2
Application number	US-201514814981-A
Country	US
Kind code	B2
Filing date	Jul 31, 2015
Priority date	Jul 31, 2015
Publication date	Apr 18, 2017
Grant date	Apr 18, 2017

Abstract

Provided is an apparatus and method for transmitting and receiving polarized signals. Wireless communication with multiple polarized signals may experience greater attenuation on one polarized signal than another polarized signal. The polarized signal that is more attenuated limits overall throughput for the wireless communication. According to an embodiment of the invention, signals undergo rotation processing with a transformation involving a rotation matrix prior to transmission. Each polarized signal that is transmitted is based on a different weighted combination of the signals. The rotation processing can be performed with an objective that signals recovered at a receiver have comparable signal quality, which can increase overall throughput. In some implementations, the rotation processing is performed based on feedback to dynamically adjust the rotation processing.

First claim

We claim:

1. An apparatus comprising:
a signal processor configured to process a first signal and a second signal with a rotation matrix to produce a first processed signal and a second processed signal such that each of the first and second processed signals is a respective different weighted combination of the first and second signals; and
a transmitter configured to wirelessly transmit the first processed signal with a first polarization, and to wirelessly transmit the second processed signal with a second polarization that is substantially orthogonal to the first polarization;
wherein the rotation matrix is a real matrix used to rotate the first signal and the second signal.

2. The apparatus of claim 1 , wherein:
the signal processor is configured to, based on received feedback, adjust an angle of rotation of the rotation matrix.

3. A method comprising:
processing a first signal and a second signal with a rotation matrix to produce a first processed signal and a second processed signal such that each of the first and second processed signals is a respective different weighted combination of the first and second signals;
wirelessly transmitting the first processed signal with a first polarization; and
wirelessly transmitting the second processed signal with a second polarization that is substantially orthogonal to the first polarization;
wherein the rotation matrix is a real matrix used to rotate the first signal and the second signal.

4. The method of claim 3 , wherein:
the rotation matrix comprises additional processing to produce the first processed signal and the second processed signal.

5. The method of claim 4 , wherein the additional processing comprises a gain.

6. The method of claim 4 , wherein:
the rotation and the additional processing are applied concurrently in a single operation.

7. The method of claim 3 , further comprising:
based on received feedback, adjusting an angle of rotation of the rotation matrix.

8. The method of claim 7 , wherein:
the received feedback comprises an indication of signal quality for signals recovered at a receiver from the first and second processed signals; and
the angle of rotation is adjusted based on the indication of signal quality.

9. The method of claim 7 , wherein the received feedback comprises an indication of an updated value to use for the angle of rotation.

10. The method of claim 7 , wherein the received feedback comprises an indication to increment the angle of rotation or an indication to de-increment the angle of rotation.

11. The method of claim 3 , wherein the rotation matrix is

[

cos
⁢

⁢
θ

-
sin

⁢

⁢
θ

sin
⁢

⁢
θ

cos
⁢

⁢
θ

]

with θ being an angle of rotation.

12. An apparatus comprising:
a receiver configured to wirelessly receive a first signal with a first polarization, and to wirelessly receive a second signal with a second polarization that is substantially orthogonal to the first polarization; and
a signal processor configured to process the first and second signals with a rotation matrix to produce a first processed signal and a second processed signal such that each of the first and second processed signals is a respective different weighted combination of the first and second signals;
wherein the rotation matrix is a real matrix used to rotate the first signal and the second signal.

13. The apparatus of claim 12 , wherein:
the signal processor is configured to determine a first signal quality of the first processed signal and a second signal quality of the second processed signal; and
the apparatus further comprises a transmitter configured to transmit feedback based on the first and second signal quality.

14. A method comprising:
wirelessly receiving a first signal with a first polarization;
wirelessly receiving a second signal with a second polarization that is substantially orthogonal to the first polarization;
processing the first and second signals with a rotation matrix to produce a first processed signal and a second processed signal such that each of the first and second processed signals is a respective different weighted combination of the first and second signals;
wherein the rotation matrix is a real matrix used to rotate the first signal and the second signal.

15. The method of claim 14 , wherein:
the rotation matrix comprises additional processing to produce the first processed signal and the second processed signal.

16. The method of claim 15 , wherein the additional processing comprises a gain.

17. The method of claim 15 , wherein:
the rotation and the additional processing are applied concurrently in a single operation.

18. The method of claim 14 , further comprising:
determining a first signal quality of the first processed signal and a second signal quality of the second processed signal; and
transmitting feedback based on the first and second signal quality.

19. The method of claim 18 , wherein transmitting the feedback based on the signal quality comprises:
transmitting the feedback in response to a determination that the first and second processed signals have different signal quality.

20. The method of claim 18 , wherein the feedback comprises an indication of the signal quality for the first and second processed signals.

21. The method of claim 18 , wherein the feedback comprises an indication of an updated value to use for an angle of rotation of the rotation matrix.

22. The method of claim 18 , wherein the feedback comprises an indication to increment an angle of rotation of the rotation matrix or an indication to de-increment the angle of rotation.

23. The method of claim 14 , wherein the rotation matrix is

[

cos
⁢

⁢

Assignees

• Aharony Ahikam
• Zamani Mahdi
• Huawei Tech Co Ltd

Inventors

• Aharony Ahikam
• Zamani Mahdi

Classifications

• H04B7/0469

  taking special antenna structures, e.g. cross polarized antennas into account · CPC title

• H04L1/0033 Primary

  arrangements specific to the transmitter · CPC title

• H04B7/0641

  Differential feedback · CPC title

• H04L1/0003

  by switching between different modulation schemes · CPC title

• H04L1/0006

  by adapting the transmission format · CPC title