1. A method of transmitting signals from a transmitter comprising two or more transmit antennas in a mobile telecommunications network, the method comprising determining channel state information, estimating reliability of the channel state information, space time block encoding at least one data sequence, before transmitting the data sequence, applying to the data sequence a linear transformation so as to at least partially compensate for channel variations, the linear transformation being dependent upon the channel state information and dependent upon the estimated reliability of the channel state information.