Mutual coupling mitigation in a multi-port antenna system

Patent metadata

Field	Value
Publication number	US-9749031-B2
Application number	US-201514681665-A
Country	US
Kind code	B2
Filing date	Apr 8, 2015
Priority date	Apr 8, 2015
Publication date	Aug 29, 2017
Grant date	Aug 29, 2017

Abstract

A system that incorporates teachings of the subject disclosure may include, for example, accessing a group of de-coupling data stored in a memory of a communication device where the group of de-coupling data is mapped to corresponding use cases associated with the communication device, selecting de-coupling data from among the group of de-coupling data according to a determined use case of the communication device, generating a pre-distortion signal according to the selected de-coupling data, combining the pre-distortion signal with RF signals to generate pre-distorted RF signals, and transmitting the pre-distorted RF signals via a multi-port antenna of the communication device. Other embodiments are disclosed.

First claim

What is claimed is:

1. A wireless communication device, comprising:
multiple ports connecting to an antenna;
a memory storing machine-readable instructions; and
an RF front end comprising a processing system including a processor coupled to the memory and the multiple ports, wherein the processing system, responsive to executing the machine-readable instructions, facilitates performance of operations comprising:
determining a use case for communications;
selecting coupling coefficients comprising a high-frequency coupling coefficient and a low-frequency coupling coefficient according to the use case based on de-coupling data stored in the memory;
generating a pre-distortion signal, wherein the pre-distortion signal comprises a high-frequency signal based on the high-frequency coupling coefficient and a low-frequency signal based on the low-frequency coupling coefficient, wherein the high-frequency coupling coefficient differs from the low-frequency coupling coefficient;
applying the pre-distortion signal to RF signals to obtain pre-distorted RF signals;
applying the pre-distorted RF signals at feeds of the multiple ports; and
transmitting the pre-distorted RF signals via the multiple ports.

2. The wireless communication device of claim 1 , wherein the multiple ports are part of a multiple-input and multiple-output antenna system, and wherein the wireless communication device is a mobile device.

3. The wireless communication device of claim 1 , wherein the multiple ports are part of a multi-mode antenna system, and wherein the wireless communication device is a mobile device.

4. The wireless communication device of claim 1 , wherein the multiple ports are part of an antenna system, and wherein the wireless communication device is not a mobile device.

5. The wireless communication device of claim 1 , wherein the operations further comprise:
determining a first mean square error of the pre-distorted RF signals; and
determining a second mean square error of the RF signals, wherein the first mean square error of the pre-distorted RF signals is less than the second mean square error of the RF signals.

6. The wireless communication device of claim 1 , wherein the generating of the pre-distortion signal according to the coupling coefficients comprises:
generating a coupling matrix using the high-frequency coupling coefficient and the low-frequency coupling coefficient;
inverting the coupling matrix to determine a de-coupling matrix; and
generating the pre-distortion signal based on the de-coupling matrix.

7. The wireless communication device of claim 1 , further comprising a baseband processor, wherein the antenna comprises a single, two-port antenna, wherein the multiple ports are associated with the single, two-port antenna, and wherein the use case includes a physical use state of the wireless communication device.

8. The wireless communication device of claim 1 , wherein the applying of the pre-distortion signal at the feeds comprises applying the pre-distortion signal at the feeds of a subset of ports of the multiple ports, wherein at least one port of the multiple ports does not receive the pre-distortion signal.

9. The wireless communication device of claim 1 , wherein the operations further comprise:
determining a change from the use case to a second use case;
selecting second coupling coefficients according to the second use case based on the de-coupling data stored in the memory;
generating a second pre-distortion signal according to the second coupling coefficients;
applying the second pre-distortion signal at the feeds of the multiple ports to additional RF signals to generate second pre-distorted RF signals; and
transmitting the second pre-distorted RF signals via the multiple ports.

10. The wireless communication device of claim 1 , wherein the determining of the use case comprises measuring a reflected power associated with the multiple ports, and wherein the applying of the pre-distortion signal to the RF signals is a linear combination.

11. The wireless communication device of claim 1 , wherein the operations further comprise provisioning the memory with the de-coupling data, wherein the de-coupling data is pre-determined by a computing device based on different antenna spacing.

12. The wireless communication device of claim 1 , further comprising a matching network including a variable reactance element, wherein the variable reactance element is adjusted according to the use case to provide impedance tuning.

13. A wireless communication device, comprising:
multiple ports connecting to a single antenna or to different antennas;
a memory storing machine-readable instructions; and
an RF front end comprising a processing system including a processor coupled to the memory and the multiple ports, wherein the processor, responsive to executing the machine-readable instructions, facilitates performance of operations comprising:
forming an estimate of multi-port antenna coupling coefficients comprising high-frequency coupling coefficients and low-frequency coupling coefficients that differ from the high-frequency coupling coefficients;
generating a pre-distortion signal by linearly combining RF signals based on computations using the multi-port antenna coupling coefficients, wherein the RF signals comprise high-frequency signals and low-frequency signals, wherein the linearly combining of the high-frequency signals are based on the high-frequency coupling coefficients and wherein the linearly combining of the low-frequency signals are based on the low-frequency coupling coefficients;
applying the pre-distortion signal at feeds of the multiple ports; and
transmitting pre-distorted RF signals via the multiple ports based on the applying of the pre-distortion signal.

14. The wireless communication device of claim 13 , further comprising a matching network including a variable reactance element, wherein the variable reactance element is adjusted according to a determined use case to provide impedance tuning.

15. A machine-readable storage medium encoded with machine-executable instructions that when executed by a processing system including a processor of an RF front end coupled to a memory and to multiple ports connecting to a single antenna or to different antennas, facilitates performance of operations comprising:
determining a use case for communications;
identifying coupling coefficients according to the use case based on de-coupling data stored in the memory, wherein the coupling coefficients comprise high-frequency coupling coefficients and different low-frequency coupling coefficients;
generating a pre-distortion signal according to the coupling coefficients, wherein the pre-distortion signal comprises a high-frequency signal based on the high-frequency coupling coefficients and a low-frequency signal based on the low-frequency coupling coefficients;
applying the pre-distortion signal to RF signals to obtain pre-distorted RF signals;
applying the pre-distorted RF signals at feeds of the multiple ports; and
transmitting the pre-distorted RF signals via the multiple ports.

16. The machine-readable storage medium of claim 15 , wherein the determining of the use case comprises measuring a reflected power associated with the multiple ports, and wherein the applying of the pre-distortion signal to the RF signals is a linear combination.

17. The machine-readable storage medium of claim 15 , wherein the operations further comprise:
determining a change from the use case to a second use case;
selecting second coupling coefficients accord

Assignees

• Blackberry Ltd

Inventors

• Ali Shirook M H
• Buckley Michael Eoin
• Bhardwaj Anmol

Classifications

• H04B17/11

  for calibration · CPC title

• H04B17/103 Primary

  Reflected power, e.g. return loss · CPC title

• H04B1/0458

  Arrangements for matching and coupling between power amplifier and antenna or between amplifying stages (matching circuits in general H03H) · CPC title

• H03F1/3241

  using predistortion circuits (H03F1/3211, H03F1/3217 take precedence) · CPC title

• H04B2001/0425

  with linearisation using predistortion · CPC title