Synchronization signal receiving method and user apparatus, and synchronization signal transmission method and base station

Provided are a method and a device whereby a synchronization signal is transmitted and received. One embodiment of the present invention involves using one of a plurality of cells (first cell hereinbelow) in order to transmit synchronization signal setting information of a cell (second cell hereinbelow) set in an unlicensed band of the plurality of cells. The synchronization signal is transmitted on the second cell, based on the synchronization signal setting information. The synchronization signal is used in order to acquire time and frequency synchronization with the second cell.