MOBILE TELECOMMUNICATION REPEATER FOR CANCELING FEEDBACK SIGNALS

• US 20140194054A1
• Filed: 03/15/2013
• Published: 07/10/2014
• Est. Priority Date: 01/08/2013
• Status: Active Grant

• Current Assignee: Advanced RF Technologies Incorporated
• Original Assignee: Advanced RF Technologies Incorporated
• Inventors: Kim, Jong-Min
• Granted Patent: US 10,305,575 B2
• Time in Patent Office: Days
• US Class Current: 455/11.1
• CPC Class Codes: H01Q 1/007 specially adapted for indoor communication
• CPC Class Codes: H01Q 21/28 Combinations of substantially independent non-interacting antenna units or systems multiple beam H01Q25/00
• CPC Class Codes: H01Q 3/2611 Means for null steering; Adaptive interference nulling
• CPC Class Codes: H03M 1/1052 using two or more look-up tables each corresponding to a different type of error, e.g. for offset, gain error and non-linearity error respectively
• CPC Class Codes: H04B 7/15507 Relay station based processing for cell extension or control of coverage area, network planning with network coordinated processing with regard to cell extension H04W16/26; network topologies using dedicated repeater stations H04W84/047; terminal devices adapted for relaying to or from an other terminal H04W88/04
• CPC Class Codes: H04B 7/15535 Control of relay amplifier gain amplifier gain control in general H03G3/00; gain control reducing self - or loop interference H04B7/15578
• CPC Class Codes: H04B 7/15542 Selecting at relay station its transmit and receive resources selection of wireless resources by user or terminal H04W72/02; arrangements affording multiple use of the transmission path by two-dimensional division of the resources H04L5/0003, or by allocating sub-channels H04L5/003
• CPC Class Codes: H04B 7/15571 by signal isolation, e.g. isolation by frequency or by antenna pattern, or by polarization
• CPC Class Codes: H04B 7/15585 by interference cancellation
• CPC Class Codes: H04L 25/24 Relay circuits using discharge tubes or semiconductor devices H04L25/22 takes precedence

Abstract

A mobile telecommunication wireless repeater includes: a combination stage for combining a received signal with a feedback cancellation signal; a comparison stage for comparing an input signal of the combination stage with an output signal of the combination stage and determining a weighted value and a time offset value for a feedback signal to be cancelled, based on the comparison; and a recombination stage comprising one or more adaptive filters and configured to receive the weighted value and the time offset value and generate the feedback cancellation signal according to the weighted value and the time offset value.

Claims

1. A mobile telecommunication wireless repeater, comprising:

a combination stage for combining a received signal with a feedback cancellation signal;

a comparison stage for comparing an input signal of the combination stage with an output signal of the combination stage and determining a weighted value and a time offset value for a feedback signal to be cancelled, based on the comparison; and

a recombination stage comprising one or more adaptive filters and configured to receive the weighted value and the time offset value and generate the feedback cancellation signal according to the weighted value and the time offset value.

2. The mobile telecommunication wireless repeater of claim 1, wherein the comparison stage is configured to determine the weighted value based on an energy difference between the feedback signal to be cancelled and the output signal of the combination stage after feedback cancellation, and provide the weighted value to the recombination stage.

3. The mobile telecommunication wireless repeater of claim 1, wherein when the feedback signal is completely cancelled, the weighted value is adjusted to a minimum value.

4. The mobile telecommunication wireless repeater of claim 1, wherein the comparison stage is configured to determine the time offset value based on a time difference between the feedback signal to be cancelled and the output signal of the combination stage after feedback cancellation, and provide the time offset value to the recombination stage.

5. The mobile telecommunication wireless repeater of claim 1, wherein the recombination stage is configured to determine a final weighted value by adding the weighted value determined by the comparison stage to an existing weighted value, and apply the final weighted value to the one or more adaptive filters.

6. The mobile telecommunication wireless repeater of claim 1, wherein the recombination stage is configured to apply the time offset value determined by the comparison stage to a delay function of the one or more adaptive filters such that a time offset of the feedback cancellation signal corresponds to a time offset of a feedback signal to be cancelled.

7. The mobile telecommunication wireless repeater of claim 1, wherein the recombination stage comprises a plurality of stages for adjusting a plurality of time offset values of a plurality of feedback signals to be cancelled.

8. The mobile telecommunication wireless repeater of claim 7, wherein the plurality of stages is configured to independently adjust each of the time offset values.

9. The mobile telecommunication wireless repeater of claim 1, wherein the recombination stage comprises a plurality of stages for adjusting a plurality of weighted values of filter coefficients of the one or more adaptive filters.

10. The mobile telecommunication wireless repeater of claim 9, wherein the plurality of weighted values respectively corresponds to a plurality of feedback signals to be cancelled and the plurality of stages is configured to independently adjust each of the weighted values.

11. The mobile telecommunication wireless repeater of claim 1, further comprising:

a receiving antenna for receiving the received wireless signal;

a down-converter stage for converting the received wireless signal to an intermediate frequency;

an Analog to Digital Converter (ADC) stage for converting the wireless signal of the intermediate frequency to a digital signal;

a Digital to Analog Converter (DAC) stage for converting the output signal of the combination stage to an analog signal of the intermediate frequency; and

an up-converter stage for converting the analog signal of the intermediate frequency to a wireless RF signal and outputting the wireless RF signal to a transmitting antenna.

12. A method of cancelling feedback from a received signal, the method comprising:

combining the received signal with a current feedback cancellation signal;

comparing the received signal before the combination with an output signal after the combination;

determining a weighted value and a time offset value of a feedback signal to be cancelled, based on the comparison;

generating, by one or more adaptive filters, a further feedback cancellation signal based on the weighted value and the time offset value; and

applying the further feedback cancellation signal in place of the current feedback cancellation signal.

13. The method of claim 12, wherein the weighted value is determined according to an energy difference between the feedback signal to be cancelled and the output signal after combination with the current feedback cancellation signal.

14. The method of claim 12, wherein the time offset value is determined according to a time difference between the feedback signal to be cancelled and the output signal after the combination with the current feedback cancellation signal.

15. The method of claim 12, further comprising determining a final weighted value by adding the weighted value to an existing weighted value, and applying the final weighted value to the one or more adaptive filters.

16. The method of claim 12, further comprising applying the time offset value to a delay function of the one or more adaptive filters such that a time offset of the further feedback cancellation signal corresponds to a time offset of a feedback signal to be cancelled.

17. A method of cancelling feedback from a received signal, the method comprising:

combining the received signal with a feedback cancellation signal;

comparing the received signal before the combination with an output signal after the combination;

determining a weighted value and a time offset value for each feedback signal of a plurality of feedback signals to be cancelled, based on the comparison; and

adjusting, by one or more adaptive filters, the feedback cancellation signal based on the weighted value and the time offset value for each of the feedback signals.