Patent ID: 8369773

Claim:
A self-excitation detecting method for a repeater, comprising: detecting an output power of an up link; judging whether the detected output power of the up link exceeds a threshold of self-excitation and, if so, adding a numerically-controlled attenuation to the up link accordingly; and judging whether the change in the output power of the up link is equal to that in the numerically-controlled attenuation and, judging whether the repeater is subject to a self-excitation according to the result of judgment regarding the change in the output power of the up link; wherein judging whether the change in the output power of the up link is equal to that in the numerically-controlled attenuation and judging whether the repeater is subject to a self-excitation according to the result of judgment comprises: detecting the output power of the up link to which the numerically-controlled attenuation has been added; comparing the detected output power of the up link to which the numerically-controlled attenuation has been added with the output power of the up link before the numerically-controlled attenuation is added, and judging whether the change in the output power of the up link is equal to that in the numerically-controlled attenuation; if they are equal, judging whether there is count in the self-excitation counter; if there is no count, confirming there is no self-excitation; if there is, confirming there is self-excitation in the repeater; if they are unequal, automatically adding 1 to the self-excitation counter, and judging whether the numerical value of self-excitation counter exceeds the preset value; confirming there is self-excitation generated in the repeater when the numerical value of self-excitation counter exceeds the preset value.