Weighted Sum Rate Maximization of the mmWave Cell-Free MIMO Downlink Relying on Hybrid Precoding

The cell-free MIMO concept relying on hybrid precoding constitutes an innovative technique capable of dramatically increasing the network capacity millimeter-wave (mmWave) communication systems. It dispenses with cell boundary conventional multi-cell systems, while drastically reducing power consumption by limiting number radio frequency (RF) chains at access points (APs). In this paper, we aim for maximizing weighted sum rate (WSR) mmWave systems conceiving a low-complexity algorithm. We formulate WSR optimization problem subject to transmit constraint each AP and constant-modulus phase shifters analog precoders. A block coordinate descent (BCD) algorithm is proposed iteratively solving problem. iteration, classic Lagrangian multiplier method penalty dual decomposition (PDD) are combined obtaining near-optimal analog/digital matrices. Furthermore, extend our deriving closed-form expressions precoders fully digital Moreover, present convergency analysis complexity method. Finally, simulation results demonstrate superiority algorithms both