Multicarrier transmit diversity in UTRAN for HSPA, comprising a baseband unit and a remote radio unit of a Node B configured for receiving a data stream from an RNC and subsequently generating N encoded data streams and corresponding RF output signals for downlink transmission over N antennas; wherein the remote radio unit transmits the N (preferably two) RF output signals using transmission diversity over different carrier frequencies. The remote radio unit can transmit each STTD encoded data stream over different frequency carriers or transmit one STTD encoded data stream over a frequency carrier at frequency f1 and the second STTD encoded data stream over a different frequency carrier, at frequency f2. The baseband unit can also transmit, using MIMO baseband processing, the N MIMO data streams over different frequency carriers.