Antenna diversity switching with hysteresis.

摘要

A diversity antenna communiation system for mounting on and use with a mobile body. The system includes at least two receiving systems having different propagation paths from one another. During the transmission, a radio wave is radiated. Upon reception, the reception levels of each receiving system are monitored to control reception. According to a first embodiment of the invention, the output signals of those receiving systems momentarily not in use are attenuated by a certain degree in order to reduce the switching frequency between receiving systems having substantially the same output level. According to a second embodiment of the invention, the output signals of those receiving systems momentarily not in use are compared with a first threshold level which is different from a second threshold level with which the momentarily used input signal is compared. <IMAGE>