Method of transmitting of data and configuring a codebook in multi antenna system

A data communications method in a multiple antenna system and a code book constitution method are provided to allocate transmission power in an MIMO system and to allocate uniform transmission power to each antenna. One or more pilot is transmitted within a first symbol area through a first antenna unit. One or more pilot is transmitted within a second symbol area through a second antenna unit. Data within the first symbol area is transmitted through the second antenna unit. Data within the second symbol area is transmitted through the first antenna unit.