Wireless transmission systems may use transmit diversity, whereby transmission is made using a plurality of antennas to transmit the signal to a receiver. Typically, such transmit diversity systems are intended to increase network capacity and improve coverage by reducing signal degradation that may be caused by multipath and fading effects. References describing various aspects of transmit diversity include include UK Patent Application GB 2353437A, entitled Diversity transmission means with phase adjustment depending upon a feedback signal supplied to the transmitter by the receiver; US Patent Application Publication No. 2003/0002594, entitled Communication device with Smart antenna using a quality-indication signal; US Patent Application Serial No. 2005/0130597, entitled Adjusting a signal at a diversity system; US Patent Application Serial No. 2005/0164645, entitled Communicating signals according to a quality indicator using multiple antenna elements; and US Patent Application Serial No. 2006/0270359, entitled Determining a phase adjustment in accordance with power trends. There is a need for an improved algorithm for control of transmit diversity.