فهرست نشریات علمی دسترسی آزاد ایران

This paper proposes a novel framework for hybrid precoding and power allocation in millimeter-wave (mmWave) multi-user massive multi input multi output  (MIMO) systems with distributed base stations (BSs). The framework addresses key challenges in mmWave communications, including high path loss, signal blockages, and hardware complexity, by exploiting the spatial diversity and architectural flexibility of distributed BS configurations. The proposed approach adopts a two-stage optimization process. First, a hybrid precoding strategy combines coarse analog beamforming with digital precoding to mitigate multi-user interference effectively. The analog and digital beamformer matrices are derived through an optimization procedure. Second, an adaptive power allocation algorithm dynamically adjusts transmit power across users and antennas based on real-time channel conditions, optimizing spectral efficiency while suppressing inter-user interference. The optimization problems are solved using Karush-Kuhn-Tucker (KKT) conditions and minimum mean square error (MMSE) criteria. Extensive simulations under various scenarios demonstrate that the proposed scheme achieves significant improvements in spectral efficiency while reducing power consumption, highlighting its potential for practical mmWave communication systems.