ISOLATION CHECKING METHOD AND A DEVICE, SPECIFICALLY IN CONNECTION WITH USING A GUARD BAND, WITHOUT GENERATING A SPECIFIC SIGNAL DURING AN ISOLATION INSPECTION

摘要

PURPOSE: An isolation checking method and a device are provided to use a guard band whose speech quality is normal, during an isolation inspection, thereby preventing speech quality from deteriorating or a call from being disabled during the isolation inspection. CONSTITUTION: A donor antenna(301) combines with a base station. A service antenna(321) communicates with a mobile terminal. A base station side duplexer(303) is combined with the donor antenna(301). A service side duplexer(319) is combined with the service antenna(321). An LNA(317) amplifies the first frequency signal. A low frequency mixer(315) mixes the first frequency signal with a predetermined frequency to convert into an IF. An SAW filter(313) filters the IF. An RF mixer(307) mixes the filtered IF with a predetermined frequency to convert into the second frequency. An HPA(305) amplifies the second frequency. A detector(323) detects a signal outputted from the HPA(305). A controller(325) controls such that the RF mixer(307) can output a guard band frequency signal, receives a detection value of the guard band frequency signal, and compares the detection value with a preset standard value to decide a degree of isolation.