A method, apparatus, and system to transmit signals using multiple antennas with per-antenna power constraints. The method includes initializing a precoding algorithm to a complex matrix. The precoding algorithm is for precoding signals transmitted by a plurality of antennas. The method includes iteratively processing the precoding algorithm on a per-antenna basis by, at each iteration, sequentially updating a precoder for each of the plurality of antennas. The method includes, after each iteration, determining whether the precoding algorithm has converged based on a change in a rate of mutual information across iterations. Additionally, the method includes, in response to determining that the precoding algorithm has converged, transmitting the signals using the precoding algorithm.