Overlapped Subarray Based Hybrid Beamforming for Millimeter Wave Multiuser Massive MIMO

For massive multiple input multiple output systems at millimeter wave (mmWave) bands, we consider an efficient hybrid array architecture, namely, overlapped subarray (OSA), and develop a Unified Low Rank Sparse (ULoRaS) recovery algorithm for hybrid beamforming in downlink multiuser scenarios. The ULoRaS scheme takes advantage of the transmit-receive coordinated beamforming procedure to achieve large array gains. It has no dimensionality constraint and can be applied to the generalized OSA architecture, including both the fully connected and the widely discussed non-OSA cases. It is shown that the proposed ULoRaS algorithm for the novel OSA design is a good compromise of the performance and the required hardware complexity.