1. A data transfer method in a radio system comprising a first transceiver and a second transceiver, of which at least the first transceiver comprises a multiple antenna system, in which method a signal transmitted by the first transceiver is measured by the second transceiver, and in which method one or more threshold values are set on the performance of the transfer channel, the method comprising comparing a parameter value representing the quality of the signal measured by the second transceiver from the signal it received with one or more threshold values, and thus determining a quality class for the performance of a MIMO common channel, coding the determined quality class by the second transceiver, the second transceiver transmitting information on the quality class to the first transceiver and determining the transmit parameters of the antenna elements of the multiple antenna system used by the first transceiver for transmission based on the quality class information.