INTERFERENCE SIGNAL CANCELLATION SYSTEM AND RELAY SYSTEM THEREFOR

PURPOSE: An apparatus for canceling a transmission feedback signal and a relay system using the same are provided to have a broad frequency characteristic by canceling the transmission feedback signal and preventing the oscillation of the same frequency repeater. CONSTITUTION: An ID signal generator(301) generates an ID signal. The first power divider(302) divides the power of the output signal of the ID signal generator(301). The first coupler(303) couples the output signal of the first power divider(302) with the output signal of a repeater(400). The second coupler(305) detects the ID signal from the output signal of the repeater(400). The first correlator(306) analyzes correlation between the output signal of the second coupler(305) and the output signal of the first power divider(302), and outputs a control signal for minimizing the ID signal. An auxiliary antenna(500) receives a transmission feedback signal outputted from a transmission antenna(100). The first phase shifter(307) receives the output signal of the first correlator(306), and adjusts the phase of the transmission feedback signal inputted through the auxiliary antenna(500). The first variable attenuator(308) receives the output signal of the first correlator(306), and adjusts the level of the transmission feedback signal inputted through the first phase shifter(307). The first delay line(304) adjusts a delay time of a signal received from a reception antenna(200). The third coupler(311) couples the signal outputted through the first variable attenuator(308) with a receiving signal through the first delay line(304), and outputs a signal in which the transmission feedback signal is cancelled from the receiving signal to the repeater(400). The second delay line(309) equalizes a delay time, required for transmitting the receiving signal of the reception antenna(200) to the third coupler(311) through the first delay line(304), with a delay time required for transmitting the signal outputted through the first variable attenuator(308) to the third coupler(311). 본 발명은 무선 통신 시스템의 중계기에서 송신안테나의 송신신호의 일부가 수신안테나로 유입되는 송신 궤환 신호를 제거하는 송신 궤환 신호 제거 장치에 대하여 개시한다. 본 발명에 따른 송신 궤환 신호 제거 장치는 보조안테나로 입력된 송신 궤환 신호를 위상 변환기와 가변 감쇠기를 통하여 변화시킨 후 수신안테나의 수신 신호와 커플링시킴으로써 수신신호에 포함된 송신궤환신호를 제거한다. 따라서 본 발명에 따른 송신 궤환 신호 제거 장치는 송신 궤환 신호를 제거하여 동일주파수 중계기의 발진을 방지할 수 있기 때문에 넓은 주파수 특성을 갖게 되어 전체 시스템의 용량을 증가시키는 효과가 있다.