A first Wireless Local Area Network (WLAN) node and a method therein for performing a transmission to a second WLAN node in a WLAN. The first WLAN node identifies a third WLAN node transmitting a first signal (S1) overheard by the first WLAN node, and determines to transmit, to the second WLAN node, a second signal (S2) based on the identity of the third WLAN node and on a received power of the first signal. When determined to transmit the second signal, the first WLAN node determines a Modulation and Coding Scheme (MCS) index value by means of a link adaptation process specific for the identified third WLAN node and transmits to the second WLAN node, the second signal using the determined MCS index.