| 摘要 |
The problem of stable communication not being possible occurs when there is a time when another system occupies an unlicensed band being used in an LTE-A system. A base station device for communicating with a terminal device in a second frequency band which differs from an exclusively usable first frequency band, the base station device having a CS determination unit for carrier-sensing in a carrier sense sub-frame set in the second frequency band, a synchronization-signal generation unit for generating a synchronization signal, and a wireless transmission unit for transmitting the synchronization signal, wherein the wireless transmission unit transmits the synchronization signal generated by the synchronization-signal generation unit when determined by the CS determination unit that another system is not communicating in the second frequency band. |
