Mitigation of radio-frequency interference at a remote radio head

• US 9,369,161 B1
• Filed: 08/12/2014
• Issued: 06/14/2016
• Est. Priority Date: 08/12/2014
• Status: Active Grant

• Current Assignee: T-Mobile Innovations LLC (Deutsche Telekom AG)
• Original Assignee: Sprint Communications Company LP (Deutsche Telekom AG)
• Inventors: Chukka, Chaitanya, Wurtenberger, Andrew M., Schmidt, Patrick Jacob, Marupaduga, Sreekar
• Primary Examiner(s): Nguyen, Duc M
• Application Number:
  US14/457,855
• Time in Patent Office: 672 Days
• Field of Search: 455/115.1, 455/115.2, 455/127.1, 455/127.2, 455/127.4, 455/226.1, 455/226.2, 455/226.3, 455/114.2, 455/114.3, 455/522
• US Class Current: 1/1
• CPC Class Codes: H03F 1/02 Modifications of amplifiers to raise the efficiency, e.g. gliding Class A stages, use of an auxiliary oscillation
• CPC Class Codes: H03F 1/0233 by using a signal derived from the output signal, e.g. bootstrapping the voltage supply
• CPC Class Codes: H03F 3/24 of transmitter output stages
• CPC Class Codes: H04B 1/0475 with means for limiting noise, interference or distortion H04B1/0483 takes precedence
• CPC Class Codes: H04B 17/309 Measuring or estimating channel quality parameters
• CPC Class Codes: H04B 17/318 Received signal strength
• CPC Class Codes: H04B 17/336 Signal-to-interference ratio [SIR] or carrier-to-interference ratio [CIR]
• CPC Class Codes: H04B 17/345 Interference values signal-to-interference ratio [SIR] or carrier-to-interference ratio [CIR] H04B17/336
• CPC Class Codes: H04B 2001/045 with means for improving efficiency
• CPC Class Codes: H04W 52/243 taking into account interferences
• CPC Class Codes: H04W 52/52 using AGC [Automatic Gain Control] circuits or amplifiers
• CPC Class Codes: H04W 88/085 Access point devices with remote components

Abstract

A method, system, and medium are provided for mitigating radio-frequency (RF) interference at a remote radio head (RRH) of a base station due to non-linearity in at least one of the RRH components. RF-interference indicators received from one or more user devices are monitored. When the RF-interference indicators indicate that RF interference at the RRH is above a predefined threshold, then a power amplifier associated with the RRH is adjusted to operate in a saturation mode thereby reducing the generation of inter-modulation products and reducing RF interference at the RRH. When the RF-interference indicators indicate that RF interference at the RRH is below the predefined threshold, then the power amplifier is adjusted to operate in an active mode thereby optimizing signal gain.

Claims

1. One or more non-transitory computer-readable media having computer executable instructions embodied thereon that, when executed, perform a method of mitigating radio-frequency (RF) interference at a remote radio head (RRH) of a base station due to non-linearity in one or more of the RRH components including at least a power amplifier, wherein the power amplifier is configured to operate in an at least an active mode and a saturation mode, the method comprising:

receiving RF-interference indicators from a plurality of user devices communicating with the base station;

using the RF-interference indicators;

adjusting the power amplifier such that the power amplifier operates in the active mode when the RF-interference indicators indicate that RF interference at the RRH is below a predefined threshold; and

adjusting the power amplifier such that the power amplifier operates in the saturation mode when the RF-interference indicators indicate that RF interference at the RRH is above the predefined threshold.

2. The media of claim 1, wherein the power amplifier includes a field-effect transistor (FET).

3. The media of claim 2, wherein the FET comprises a metal-oxide-semiconductor FET (MOSFET).

4. The media of claim 1, wherein the RF-interference indicators comprise one or more of received signal strength indication (RSSI), reference signal received power (RSRP), bit error rate (BER), block error rate (BLER), signal-to-noise ratio (SNR), and signal-to-interference-plus-noise ratio (SINR).

5. The media of claim 1, wherein the predefined threshold is configured by a wireless-telecommunications-network associated with the base station.

6. The media of claim 1, wherein adjusting the power amplifier such that the power amplifier operates in the active mode comprises adjusting the biasing voltage of the power amplifier.

7. The media of claim 1, wherein adjusting the power amplifier such that the power amplifier operates in the saturation mode comprises adjusting the biasing voltage of the power amplifier.

8. A remote radio head (RRH) system of a base station, the RRH system comprising:

a first non-linear power amplifier;

a second linear power amplifier; and

a logic unit programmably coupled to both the first non-linear power amplifier and the second linear power amplifier, the logic unit adapted to;

monitor radio-frequency (RF) interference at the RRH,

activate the first non-linear power amplifier when the RF interference is below a predefined threshold, and

activate the first non-linear power amplifier and the second linear power amplifier when the RF interference is above the predefined threshold.

9. The system of claim 8, wherein the first non-linear power amplifier is serially-coupled to the second linear power amplifier.

10. The system of claim 8, wherein monitoring the RF interference at the RRH system comprises receiving a plurality of RF-interference indicators from one or more user devices communicating with the base station.

11. The system of claim 10, wherein the plurality of RF-interference indicators comprises one or more of received signal strength indication (RSSI), reference signal received power (RSRP), bit error rate (BER), block error rate (BLER), signal-to-noise ratio (SNR), and signal-to-interference-plus-noise ratio (SINR).

12. The system of claim 8, wherein the predefined threshold is configured by a wireless-telecommunications-network associated with the base station.

13. A computerized method carried out by at least one server having at least one processor for mitigating radio-frequency (RF) interference at a remote radio head (RRH) system of a base station due to non-linearity in at least one of the RRH components, the method comprising:

monitoring RF-interference indicators received from a plurality of user devices communicating with the base station;

determining that the RF-interference indicators indicate at least one of;

     1) that RF interference at the RRH system is above a predefined threshold, or

     2) that RF interference at the RRH system is below the predefined threshold, wherein;

when the RF interference is above the predefined threshold, adjusting the at least one of the RRH components such that the at least one component is operating in a saturation mode; and

when the RF interference is below the predefined threshold, adjusting the at least one component such that the at least one component is operating in an active mode.

14. The computerized method of claim 13, wherein the RF interference is due to intermodulation products produced by the at least one component.

15. The computerized method of claim 13, wherein the at least one component comprises a power amplifier.

16. The computerized method of claim 15, wherein the power amplifier includes a field-effect transistor (FET).

17. The computerized method of claim 15, wherein the power amplifier comprises a low-noise amplifier.

18. The computerized method of claim 15, wherein the power amplifier comprises a high power amplifier.

19. The computerized method of claim 13, wherein the RF-interference indicators comprise one or more of received signal strength indication (RSSI), reference signal received power (RSRP), bit error rate (BER), block error rate (BLER), signal-to-noise ratio (SNR), and signal-to-interference-plus-noise ratio (SINR).

20. The computerized method of claim 13, wherein adjusting the at least one of the RRH components such that the at least one component is operating in the saturation mode comprises adjusting the biasing voltage of the at least one component, and wherein adjusting the at least one of the RRH components such that the at least one component is operating in the active mode comprises adjusting the biasing voltage of the at least one component.