Beamforming in large-scale MIMO multiuser links under a per-node power constraint

Large-scale multiple-input multiple-output (MIMO) systems use a large array of nodes to offer high communication performance to multiple mobile users. For such systems to be economically practical, each node participating in the large-scale link likely has limited transmit power capability, and therefore properly limiting the per-node transmit power must be incorporated into the signal processing algorithm. This work generalizes an iterative beamforming algorithm for multiuser MIMO signaling, subject to such a per-node power constraint, that can accommodate nonlinear precoding and detection. Simulations using the algorithm for large-scale MIMO systems reveal that the approach can offer performance similar to that obtained with a more traditional sum-power constraint without the wide range of per-antenna transmit power distribution typical of such a constraint.