An embodiment control method for a radio device for a vehicle includes determining whether to scan alternative broadcasts based on a signal quality of a listening broadcast, wherein each of the alternative broadcasts has a same content as the listening broadcast and is a radio broadcast having a frequency or a polarization that is different from the frequency or the polarization of the listening broadcast, scanning the alternative broadcasts, comparing the signal quality of the listening broadcast with signal qualities of the alternative broadcasts to determine to switch the listening broadcast to a selected one of the alternative broadcasts, and in response to a determination to switch the listening broadcast to the selected alternative broadcast, switching the listening broadcast to the selected alternative broadcast.

An embodiment control method for a radio device for a vehicle includes determining whether to scan alternative broadcasts based on a signal quality of a listening broadcast, wherein each of the alternative broadcasts has a same content as the listening broadcast and is a radio broadcast having a frequency or a polarization that is different from the frequency or the polarization of the listening broadcast, scanning the alternative broadcasts, comparing the signal quality of the listening broadcast with signal qualities of the alternative broadcasts to determine to switch the listening broadcast to a selected one of the alternative broadcasts, and in response to a determination to switch the listening broadcast to the selected alternative broadcast, switching the listening broadcast to the selected alternative broadcast.

A method for controlling a radio apparatus for a vehicle, includes: determining of scanning determining whether to scan alternative broadcasts based on a signal quality of a listening broadcast; scanning the alternative broadcasts; determining of noise determining noise types of the alternative broadcasts based on a plurality of polarizations; comparing and determining comparing signal qualities of the listening broadcast and the alternative broadcasts based on a determination result of the determining of noise and determining whether to switch the listening broadcast to one of the alternative broadcasts; and switching the listening broadcast to the alternative broadcast based on a determination result of the comparing and determining.

A method for controlling a radio apparatus for a vehicle, includes: determining of scanning determining whether to scan alternative broadcasts based on a signal quality of a listening broadcast; scanning the alternative broadcasts; determining of noise determining noise types of the alternative broadcasts based on a plurality of polarizations; comparing and determining comparing signal qualities of the listening broadcast and the alternative broadcasts based on a determination result of the determining of noise and determining whether to switch the listening broadcast to one of the alternative broadcasts; and switching the listening broadcast to the alternative broadcast based on a determination result of the comparing and determining.