a determinant of the following equation 12 x s3 i x s3 i n x s3 i n n u2212 1 t equation 12 for example two output signals of the output signal selector 30 in an interference cancellation apparatus according to another exemplary embodiment shown in fig2 may be obtained by selecting two sector antenna incident signals when a value of the output signal of the adaptive noise canceller 40 u2032 is the smallest after obtaining every output signal of the adaptive noise canceller 40 u2032 while setting one sector antenna incident signal as the serving base station signal fig3 is a block diagram illustrating a repeater system to which the adaptive interference cancellation apparatus shown in fig2 is applied a mobile communication repeater system shown in fig3 may include three adaptive noise cancellers 40 a 40 b and 40 c setting each of three sector antenna incident signals as a serving base station signal and may selectively output only an output signal of the adaptive noise canceller outputting the smallest value among real time output signals of the adaptive noise cancellers 40 a 40 b and 40 c though a multiplexer mux 50 the adaptive interference cancellation apparatus for cancelling the side lobe between the neighboring cells of the present.