A device for measuring a reflection coefficient of an antenna includes processing circuitry configured to extract a first feedback signal and a second feedback signal from a third feedback signal based on first symbol information of a first symbol included in a radio frequency (RF) transmit signal transferred to the antenna, the first feedback signal corresponding to at least a portion of a cyclic prefix portion of the first symbol, the second feedback signal corresponding to at least a portion of a back-end portion of the first symbol, the third feedback signal being generated from a portion of the RF transmit signal provided by a coupler, and compute the reflection coefficient based on the first feedback signal and the second feedback signal.