Method for obtaining uplink calibration values, calibration method, and corresponding terminal and base station

A Base Station (BS), having a number of antennas divided into a number of groups of antennas, the BS comprising:

• a receiver, configured to cooperate with a processor to receive an uplink calibration signal from a terminal, the uplink calibration signal comprising an uplink calibration value for each antenna and a different normalization value for each antenna group, wherein the uplink calibration value is obtained from a downlink channel estimate value for each antenna and the different normalization value for each antenna group;
• the different normalization value for each antenna group is obtained from a downlink channel estimate value with a lowest signal power within each group, and
• the processor, configured to process each received uplink calibration value and each received different normalization value into a respective hardware chain value for each antenna of the number of antennas.

A calibration method for determining hardware chain values in a Base Station (BS), having a number of antennas grouped in a number of groups, wherein a respective hardware chain value for each antenna of the number of antennas is obtained, the method comprising:

• receiving, by the BS, an uplink calibration signal from a terminal, the uplink calibration signal comprising an uplink calibration value for each antenna and a different normalization value for each group of antennas, wherein the uplink calibration value is obtained from a downlink channel estimate value for each antenna and the different normalization value for each antenna group;
• the different normalization value for each antenna group is obtained from a downlink channel estimate value with a lowest signal power within each group, and
• processing, by the BS, each received uplink calibration value and each received different normalization value into the respective hardware chain value for each antenna.