METHOD AND APPARATUS FOR TUNING FINITE IMPULSE RESPONSE FILTER IN IN-BAND FULL DUPLEX TRANSCEIVER

• US 20160380799A1
• Filed: 06/21/2016
• Published: 12/29/2016
• Est. Priority Date: 06/25/2015
• Status: Active Grant

• Current Assignee: Electronics and Telecommunications Research Institute
• Original Assignee: Electronics and Telecommunications Research Institute
• Inventors: CHANG, Kapseok, JU, Hyung Sik
• Granted Patent: US 10,177,894 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H03H 15/023 with parallel-input configuration
• CPC Class Codes: H03H 2015/007 Programmable filters
• CPC Class Codes: H04B 1/123 using adaptive balancing or compensation means adaptive filter circuits and algorithms H03H
• CPC Class Codes: H04B 1/525 with means for reducing leakage of transmitter signal into the receiver
• CPC Class Codes: H04J 11/004 using regenerative subtractive interference cancellation
• CPC Class Codes: H04L 2025/03815 Transmission of a training request
• CPC Class Codes: H04L 27/265 Fourier transform demodulators, e.g. fast Fourier transform [FFT] or discrete Fourier transform [DFT] demodulators H04L27/26524 takes precedence
• CPC Class Codes: H04L 5/14 Two-way operation using the same type of signal, i.e. duplex
• CPC Class Codes: H04L 5/1461 Suppression of signals in the return path, i.e. bidirectional control circuits

Abstract

A method and an apparatus for tuning an FIR filter in an in-band full duplex transceiver. The method for tuning an FIR filter may include: setting attenuation of the FIR filter to be a first value and then estimating input information of the FIR filter; estimating a delta response using the estimated input information of the FIR filter; and updating the attenuation of the FIR filter to a second value using the estimated delta response.

Claims

1. A method for tuning a finite impulse response (FIR) filter in an in-band full duplex transceiver, the FIR filter receiving a transmission signal to cancel a self-transmitted interference signal, the method comprising:

setting attenuation of the FIR filter to be a predetermined first value and then estimating input information of the FIR filter;

estimating a delta response using the input information of the FIR filter;

updating the attenuation to a second value using the delta response; and

applying the second value to the FIR filter.

2. The method of claim 1, wherein:

the delta response corresponds to a value obtained by subtracting a baseband equivalent time impulse response for the FIR filter set as the first value from a baseband equivalent time impulse response for a radio channel.

3. The method of claim 1, wherein:

the updating includes

calculating a third value that is the attenuation of the FIR filter to be updated by using the delta response; and

calculating the second value by adding the third value to the first value.

4. The method of claim 1, wherein:

the estimating of the input information of the FIR filter includes;

setting the attenuation to be the first value and then generating and transmitting a first training signal, in a first period;

measuring a first signal that is a baseband equivalent signal for a signal obtained by subtracting an output signal of the FIR filter from the self-transmitted interference signal, in the first period;

generating and transmitting a second training signal in a second period;

measuring a second signal that is a baseband equivalent signal for the self-transmitted interference signal, in the second period; and

estimating the input information of the FIR filter using the first signal and the second signal.

5. The method of claim 4, wherein:

the estimating of the delta response includes estimating the delta response using the input information of the FIR filter and the first signal.

6. The method of claim 4, wherein:

the estimating of the input information of the FIR filter includes;

subtracting the first signal from the second signal to generate a third signal that is a baseband equivalent signal for the output signal of the FIR filter; and

calculating the input information of the FIR filter using the third signal.

7. The method of claim 4, wherein:

the measuring of the second signal includes suppressing the output signal of the FIR filter from being generated and then measuring the second signal.

8. The method of claim 4, wherein:

the first training signal and the second training signal are the same signal.

9. The method of claim 4, wherein:

the input information of the FIR filter includes a linear component and a nonlinear component.

10. The method of claim 4, wherein:

the first period and the second period are included in a field for transmitting the first training signal and the second training signal in a time domain frame.

11. An in-band full duplex transceiver, comprising:

a transmitter generating and transmitting a transmitted signal;

a receiver converting a received signal into a baseband frequency signal and demodulating the converted signal;

a finite impulse response (FIR) filter receiving the transmitted signal to cancel a self-transmitted interference signal; and

an estimator estimating input information of the FIR filter by performing fast Fourier transform (FFT) on output information of an analog digital converter included in the receiver and setting attenuation of the FIR filter using the input information of the FIR filter.

12. The in-band full duplex transceiver of claim 11, wherein:

the estimator sets the attenuation to be a first value and then estimates the input information of the FIR filter, estimates a delta frequency response using the input information of the FIR filter, updates the attenuation to a second value using the delta frequency response, and applies the second value to the FIR filter.

13. The in-band full duplex transceiver of claim 12, wherein:

the delta frequency response corresponds to a value obtained by subtracting a frequency response for the FIR filter set as the first value from a frequency response for a radio channel.

14. The in-band full duplex transceiver of claim 12, wherein:

the transmitter generates and transmits a first training signal in a first period and generates and transmits a second training signal in a second period, and

the estimator

sets the attenuation to be the first value and then performs the FFT on the output information of the analog digital converter to acquire a first signal, in the first period, and

performs the FFT on baseband equivalent information for the self-transmitted interference signal to acquire a second signal, in the second period.

15. The in-band full duplex transceiver of claim 14, wherein:

the estimator subtracts the first signal from the second signal to calculate a third signal and uses the third signal to calculate the input information of the FIR filter.

16. The in-band full duplex transceiver of claim 14, wherein:

the estimator sets the attenuation of the FIR filter in the second period to suppress an output signal of the FIR filter.

17. The in-band full duplex transceiver of claim 11, further comprising:

an antenna transmitting the transmitted signal to receive the received signal; and

a distributor transmitting the transmitted signal to the antenna and transmitting the received signal to the receiver.

18. The in-band full duplex transceiver of claim 14, wherein:

the first training signal and the second training signal are the same signal.

19. A method for tuning a finite impulse response (FIR) filter in an in-band full duplex transceiver, the in-band full duplex transceiver including a transmitter generating and transmitting a transmitted signal, a receiver converting a received signal into a baseband frequency signal, and the FIR filter receiving the transmitted signal to cancel a self-transmitted interference signal, the method comprising:

setting attenuation of the FIR filter to be a first value and then generating and transmitting a first training signal, in a first period;

performing FFT on output information of an analog digital converter included in the receiver to acquire a first signal, in the first period;

generating and transmitting a second training signal in a state in which an output signal of the FIR filter is suppressed, in a second period;

performing the FFT on the output information of the analog digital converter to acquire a second signal, in the second period;

estimating input information of the FIR filter using the first signal and the second signal;

estimating a delta frequency response using the input information of the FIR filter;

updating the attenuation to a second value using the delta frequency response; and

applying the second value to the FIR filter.

20. The method of claim 19, wherein the delta frequency response corresponds to a value obtained by subtracting a frequency response for the FIR filter set as the first value from a frequency response for a radio channel.