A method for transmitting data in a wireless local area network, and a device therefore are discussed. The method according to one embodiment includes generating, by a transmitter, a very high throughput (VHT)-SIG-A field; generating, by the transmitter, a VHT-SIG-B field by applying a single column vector; and transmitting, by the transmitter, a physical layer protocol data unit (PPDU) to a receiver, the PPDU including the VHT-SIG-A field and the VHT-SIG-B field. The single column vector is obtained from a number of spatial streams for the receiver.