The present invention relates to a first node (1) in a wireless communication system (2), where the first node (1) comprises at least two antenna ports (3, 4), and is arranged for communication with a second node (5) via a channel (H) by means of at least one antenna radiation lobe (6, 7, 8, 9). The second node (5) comprises at least two antenna ports (10, 11) and is positioned at a certain direction (12) in relation to the first node (1), and is arranged for transmitting one of at least two precoding weight set requests to the first node (1) at certain times. Each transmitted precoding weight set request is chosen in dependence of the channel (H) such that the first node (1) receives instructions for a certain beam-forming. The first node (1) is arranged to apply such a beam-forming that the precoding weight set requests received from the second node (5) have one certain distribution, of a set of at least one certain distribution, over a certain time period.