Embodiments of the present disclosure provide methods and apparatuses for base station antenna calibration. A method is implemented in a base station for a cellular communications system. The method includes configuring a user equipment, UE, for a plurality of channel state information, CSI, reports associated to respective CSI reporting bands, the respective CSI reporting bands being either: (a) different subsets of sub-bands within a downlink bandwidth of the base station or (b) different downlink bandwidth parts served by the base station; receiving the CSI reports from the UE; estimating phase and delay errors for a plurality of transmit antenna branches of the base station; compensating for the estimated phase and delay errors for the transmit antenna branches based on the CSI reports received from the UE; and transmitting a downlink signal while compensating for the estimated phase and delay errors for the transmit antenna branches of the base station.