DIGITAL RADIO WAVE RECEIVER APPLYING MULTILEVEL FREQUENCY SHIFT MODULATING SYSTEM

摘要

PURPOSE: To normally make possible correct level judging in accordance with a reception state in a case under a strong reception electric field or a weak reception electric field. CONSTITUTION: A reception electric field strength degree detected by a reception electric field strength detecting circuit 21 is monitored in a threshold value control circuit 20a under the usage of a four-phase FSK radio wave receiver and a code judging threshold value is adaptively and variably controlled in accordance with the change of the reception electric field strength so as to be supplied to a decoder 16.