A transceiver and a method of controlling data transmission in a radio
system, the method comprising transmitting packets from a first
transceiver to a second transceiver, each packet having a given quality
of service value. The first transceiver selects a stream of two or more
available streams realized with a plurality of transmit antenna paths for
the transmission of each packet on the basis of the quality of service
value of each packet and the channel quality information of each
available stream.