A method for interference alignment in wireless network having 3 transmitters and 3 receivers which are equipped with M antennas is provided. The method comprising: transmitting, performed by each of the 3 transmitters, a pilot signal known to the 3 receivers; estimating, performed by each of the 3 receivers, each channel from transmitter; transmitting, performed by each of the 3 receivers, feedback information to target transmitter; and determining, performed by transmitter 2 and transmitter 3, a precoding vector; wherein a degree of freedom(DoF) of a transmitter 1 is (M/2−α), a DoF of the transmitter 2 or the transmitter 3 is M/2.