A base station device includes: a receiver, which, in operation, receives signals from one or more other base station devices in a system using an adjacent frequency band; a searcher, which, in operation, searches for one or more center frequencies of signals from the one or more other base station devices; a selector, which, in operation, selects a synchronization target base station device from which a respective center frequency has been acquired from among the one or more other base station devices; and a controller, which, in operation, sets an operation parameter to establish synchronization with transmission and reception timings of the synchronization target base station device.