A method of transmitting data using cyclic delay in a multi-antenna system using a plurality of subcarriers and a transceiver supporting the same are disclosed. More particularly, a method of selecting a matrix (second matrix) for transforming a precoding matrix (first matrix) into a unitary matrix from a codebook by a prescribed reference is disclosed. An index for selecting the second matrix is calculated by a prescribed modulo operation in an open loop system or delivered as feedback information in a closed loop system. Diversity can be obtained by switching each column of the selected second matrix in accordance with time. In a multi-user system, a single second matrix can be determined by combining columns of the second matrix selected by each user.