Method and apparatus for tuning finite impulse response filter in in-band full duplex transceiver

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

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, by the in-band full duplex transceiver, attenuation of the FIR filter to be a first value and then generating and transmitting a first training signal, in a first period;
• performing, by the in-band full duplex transceiver, 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, by the in-band full duplex transceiver, a second training signal in a state in which an output signal of the FIR filter is suppressed, in a second period;
• performing, by the in-band full duplex transceiver, the FFT on the output information of the analog digital converter to acquire a second signal, in the second period;
• estimating, by the in-band full duplex transceiver, input information of the FIR filter using the first signal and the second signal;
• estimating, by the in-band full duplex transceiver, a delta frequency response using the input information of the FIR filter,
• updating, by the in-band full duplex transceiver, the attenuation to a second value using the delta frequency response;
• and
• applying, by the in-band full duplex transceiver, the second value to the FIR filter.