A method in a first base station for obtaining channel state information from a user equipment is provided. The first base station is comprised in a wireless communication system. The wireless communication system further comprises the user equipment. The first base station estimates (403) a first offset value for a first set of subframes based on a first channel information. The first base station further estimates (404) a second offset value for a second set of subframes based on a second channel information. The first base station transmits (405) the estimated first offset value and the estimated second offset value to the user equipment. The first base station then obtains (407) channel state information from the user equipment. The channel state information is based on the transmitted estimated first offset value and the estimated second offset value. The channel state information is to be used for transmission in the first base station.