An Overlapped Sub-array Hybrid Beamforming Architecture with Successive Interference Cancellation and Water-filling in Massive MIMO Systems

Abstract

Over the years, wireless communication has significantly improved the data rate of mobile users. The key drive behind this success is the technological advancement in wireless communication. In the physical layer, hybrid beamforming has revolutionized the way signal reaches the user by constructively adding the signal at the destination thus improving the performance. Many researchers works have proposed different algorithms to solve for optimal hybrid beamforming. However, there is no single algorithm that can achieve both high spectral efficiency and energy efficiency at the same time. This work proposes a hybrid algorithm that combines successive interference cancellation and water filling and applies this algorithm in overlapped sub-array architecture (OSA). The former can successfully optimize for analog precoding in a subarray environment as it eliminates the interference between the successive sub-arrays. While the latter can allocate the power in each data stream proportionally, thus improving the spectral efficiency. The simulation results show that the proposed algorithm with OSA can achieve a near optimal performance in comparison to fully connected hybrid beamforming (FCH) and significantly larger performance in comparison to partially connected hybrid beamforming (PCH). Moreover, the proposed algorithm achieves 89.2% energy efficiency in comparison to PCH architecture. These results show that an OSA system with the proposed algorithm provides a better tradeoff between achieved spectral efficiency (SE) and energy efficiency (EE).