A UE performs a cell activation process in a wireless network. The UE calculates a first automatic gain control (AGC) setting based on downlink signals from a base station. The downlink signals include a coarse beam reference signal, a fine beam reference signal, and a conversion indication that indicates a power conversion between the coarse beam reference signal and the fine beam reference signal. The UE further calculates a second AGC setting based on the first AGC setting and the conversion indication. The UE performs a cell search using one of the first AGC setting and the second AGC setting, and performs fine time-frequency tracking using the other of the first AGC setting and the second AGC setting.