A method and user equipment (UE) for transmitting a signal to a base station in a multi-antenna wireless communication system are discussed. The method can include mapping interleaver input vector sequences to an interleaver matrix, wherein each of the interleaver input vector sequences comprises vectors having a bit size of NL·Qm, wherein Qm is a modulation order and NL is a number of transmission layers, reading out the interleaver matrix column by column for obtaining output bit sequences, and transmitting the output bit sequences through the transmission layers to the base station.