This invention presents methods for power allocation for each data stream on each transmitting antennas in MU-MIMO wireless communication systems comprising the BS computing the temporary beamforming matrix, constructing special matrices and vectors with the maximum transmitting power on each antenna, the allocated power to each data stream, the channel quality of each data stream, and the amplitude of each element of the temporary beamforming matrix, calculating the power allocated to each data stream on each antenna with the calculated special matrices and vectors, and adjusting each element of the temporary beamforming matrix to obtain the final beamforming matrix.