Low Complexity Antenna Array Concept Using Overlapped Subarray Based Hybrid Beamforming

Hybrid beamforming communication systems allow the reduction of digital channels by splitting the precoding into a digital and analogue part. This approach makes the transmission of multiple data streams using large-scale antenna arrays in millimetre wave regime practicable. Finding a trade-off between analogue circuit complexity and achievable data rates let overlapped subarray-based hybrid beamforming architectures appear promising. Nevertheless, a high degree of overlap strongly increases the complexity and costs of such systems. Within this work, we propose two overlap methods for interconnecting adjacent subarrays. The presented methods can be implemented with low additional hardware effort. Within this work, the methods are evaluated in a downlink mobile communication scenario between a mobile radio base station comprising the two-dimensional overlapped subarray-based hybrid beamforming architecture and a mobile user. The superiority of the proposed low complexity overlap methods over the subarray-based hybrid beamforming approach is shown for a large-scale antenna array system.