METHOD FOR DETECTING DETERIORATION OF RECEPTION SENSITIVITY

摘要

PURPOSE:To detect automatically a reception circuit causing deterioration of the sensitivity by obtaining an integration mean value of a level difference of each reception circuit in an angular diversity reception system having plural reception circuits. CONSTITUTION:Outputs of plural directivity antennas 10a-10f are connected cyclically to three sets of reception circuits 40A-40C via a switching circuit 30. Outputs of the reception circuits 40A-40C are selected by a gate circuit 60 and the result is outputted to the post-stage. A control circuit 50 controls the switching circuit 30 so that a reception level of each reception circuit is a prescribed value or over. Further, the control circuit 50 detects the reception level of each reception circuit every time the talking is started, and integrates its level difference at each circuit. A mean value is obtained by dividing the integration value by means of number of times of talking and the reception circuit whose sensitivity is deteriorated is detected by the mean value.