Massive MIMO System Partitioning for Efficient Hybrid Beamformer Optimization

Hybrid analog-digital beamforming is an effective approach for practical implementations of a massive multiple-input multiple-output (MIMO) system by reducing the number of radio frequency (RF) chains. Fully connected hybrid beam-forming (F-HBF), where each RF chain is connected to each antenna, can lower hardware complexity, power consumption, and cost compared to digital beamforming. Subarray-based hybrid beamforming (S-HBF), where a specific group of RF chains is allocated to a particular subarray, can further reduce hardware requirements. The antenna array is divided into subarrays using effective partitioning so that the optimization of analog beamforming can be shared across multiple subarrays, substantially reducing computational complexity.