The present invention relates to a wireless access system, and provides methods for transmitting downlink data with a new carrier type (NCT) by using transmission diversity and devices for supporting same. According to one embodiment of the present invention, a method for user equipment receiving downlink data in the wireless access system supporting the new carrier type (NCT) comprises the steps of: receiving an upper layer signal comprising indication information indicating demodulation of downlink data into a user equipment-specific reference signal (URS), wherein the downlink data is transmitted by means of a distributed virtual resource block (DVRB) technique; receiving the downlink data and the URS transmitted using the DVRB technique by applying different precoding matrices to a first slot and a second slot in a subframe; demodulating the URS and estimating channel information with respect to the first slot and the second slot; and demodulating downlink data based on the channel information.