A radio base station and a method therein for scheduling an uplink radio resource to a first user equipment in a wireless communication system which employs CDMA are provided. The method includes measuring an Interference Suppression (IS) gain for each user equipment in a set of user equipments currently being served by the radio base station. The method further includes determining a user constellation pertaining to information regarding the different user equipments in the set of user equipments and their respective bitrates, and updating a table of IS gains with the measured IS gain in bins corresponding to the determined user constellation. The method further includes predicting a load based on at least the updated table, and scheduling the uplink radio resource to the first user equipment at least partly based on the predicted load.