| 摘要 |
A method of activating a secondary cell in a base station of an LTE communication system, wherein the secondary cell is an unlicensed carrier, the method comprising: performing, by the base station, a clear channel assessment on the secondary cell to determine whether the secondary cell is idle; transmitting, by the base station, a preamble signal on the secondary cell when the secondary cell is idle, wherein the preamble signal includes information indicating that the base station activates the secondary cell. |
