Methods and apparatuses are provided for uplink MIMO transmissions in a wireless communication system. In particular, an enhanced pilot reference may be provided for enabling increased data rates on a secondary stream. Specifically, a primary stream, provided on a primary virtual antenna, includes an enhanced primary data channel E-DPDCH, a primary control channel DPCCH, and an enhanced primary control channel E-DPCCH. Further, a secondary stream, provided on a secondary virtual antenna, includes an enhanced secondary data channel S-E-DPDCH and a secondary control channel S-DPCCH. Here, the secondary control channel S-DPCCH may be transmitted at a boosted power level relative to a determined reference power level.