Method and arrangement in a base station for adjusting a channel quality indicator value of a wireless transmission between the base station and a user equipment. The base station, the user equipment and a relay node are comprised in a multi-hop wireless communication system and adapted to intercommunicate in a first transmission mode and a second transmission mode. The method comprises sending a radio signal to be received by the user equipment, obtaining a measurement of the channel quality indicator value, determining if the transmission mode of the sent radio signal is different from the transmission mode of the obtained channel quality indicator value measurement, and adding a channel quality indicator offset value to the channel quality indicator value, if the transmission mode of the relay node is determined to be the first transmission mode while the channel quality indicator was measured and obtained in the second transmission mode.