Repeater and interference cancellation method thereof
A method of operating a repeater comprises selecting some of adaptive filter coefficients among a plurality of adaptive filter coefficients of an adaptive filter used for interference cancellation, based on the size of a coefficient, generating a predicted interference signal using the selected adaptive filter coefficients and generating an interference-canceled communication signal from a received signal using the generated predicted interference signal.
1 . A method of operating a repeater, the method comprising:
generating a plurality of adaptive filter coefficients of an adaptive filter based on a received signal;
selecting, from the generated plurality of adaptive filter coefficients, some of adaptive filter coefficients for interference cancellation, based on a size of a coefficient;
generating a predicted interference signal using the selected adaptive filter coefficients; and
generating an interference-canceled communication signal from a received signal using the generated predicted interference signal.
2 . The method of claim 1 , wherein the adaptive filter is a finite impulse response (FIR) filter.
3 . The method of claim 1 , wherein the selecting of some of adaptive filter coefficients based on the size of the coefficient comprises:
selecting the some of the adaptive filter coefficients based on an absolute value size of a coefficient.
4 . The method of claim 1 , further comprising:
sorting the plurality of adaptive filter coefficients according to an absolute value size of a coefficient, and
wherein the selecting of some of adaptive filter coefficients based on the size of the coefficient comprises:
selecting some of the adaptive filter coefficients having an upper absolute value size according to a sorted order.
5 . The method of claim 4 , the selecting of some of adaptive filter coefficients based on the size of the coefficient comprises:
selecting K adaptive filter coefficients from among N of the adaptive filter coefficients, wherein N is a natural number of 2 or more, and K is a natural number less than N.
6 . The method of claim 5 , wherein a ratio of the N and the K is a preset value.
7 . The method of claim 5 , wherein a ratio of the N and the K is set flexibly.
8 . The method of claim 7 , further comprising:
searching for a point where an absolute value difference between adjacent coefficients is greater than a reference value when the adaptive filter coefficients are sorted in an order of absolute value size of a coefficient, and
wherein the selecting of some of adaptive filter coefficients based on the size of the coefficient comprises:
selecting some of the adaptive filter coefficients having an upper absolute value size according to the order of absolute value size of a coefficient, based on the searched point.
9 . The method of claim 5 , wherein a ratio of the N and K is set according to quality of service (QOS).
10 . A repeater comprising:
a controller configured to:
generate a plurality of adaptive filter coefficients of an adaptive filter based on a received signal; and
select, from the generated plurality of adaptive filter coefficients, some of adaptive filter coefficients for interference cancellation, based on a size of a coefficient, and output the selected adaptive filter coefficients;
the adaptive filter configured to generate a predicted interference signal using the selected adaptive filter coefficients; and
a subtracter configured to generate an interference-canceled communication signal from a received signal using the generated predicted interference signal.
11 . The repeater of claim 10 , wherein the controller is configured to sort the plurality of adaptive filter coefficients according to an absolute value size of a coefficient, and to select some of the sorted plurality of adaptive filter coefficients having an upper absolute value size according to an order of absolute value size.
12 . The repeater of claim 11 , wherein the controller is configured to select K adaptive filter coefficients from among N of the adaptive filter coefficients,
wherein N is a natural number of 2 or more, and K is a natural number less than N.
13 . The repeater of claim 12 , wherein a ratio of the N and the K is set flexibly.
14 . The repeater of claim 13 , wherein the controller, when the adaptive filter coefficients are sorted in the order of absolute value size, is configured to search for a point where an absolute value difference between adjacent coefficients is greater than a reference value, and to select some of the adaptive filter coefficients having an upper absolute value size according to a sorted order based on the searched point.
15 . The repeater of claim 12 , wherein a ratio of the N and the K is set according to quality of service (QOS).