METHOD AND ARRANGEMENT IN A WIRELESS COMMUNICATIONS SYSTEM

A method for assisting the adaptation of a signal from a first node (100) to a second node (120) is provided. The first node communicates with the second node in a wireless communication system (110) over a radio link (130). The second node is configured to comprise a codebook, which codebook comprises a set of possible information alternatives used for assisting the adaptation of a signal from the first node to the second node. The second node may select an information alternative from a codebook and send it to the first node to assist the first node how to adapt the signal. The first node is arranged to know a number of subsets, each subset comprising a part of possible information alternatives. The method comprises the steps of sending a configuration request to the second node to restrict the selection of information alternatives to one of the subsets; receiving an information alternative from the second node, which is selected among the at least one subsets configured according to the configuration request.