The present solution relates to a method in a first communication node (201) for determining an indication of channel quality of a radio channel (205) between the first communication node (201) and a second communication node (203). The first communication node (201) and the second communication node (203) are comprised in a wireless communication network (200). The radio channel (205) comprises a plurality of sub bands. First, at least two channel quality reports are obtained (701) for different time instances. Each channel quality report comprises indications of channel quality of at least two of the plurality of sub bands. Then a channel quality deviation is estimated (702) for at least one of the plurality of sub bands. Further, an indication of a channel quality is determined (703) for at least one of the plurality of sub bands based on the estimated channel quality deviation.