Distributed Uplink Transmission for Mid-Band Extra Large-Scale MIMO Systems

Mid-band extra large-scale massive multiple-input multiple-output (XL-MIMO) systems are regarded as potential enablers in future communication systems, which are also trapped in high complexity and channel state information (CSI) acquisition overhead. In this paper, an efficient distributed XL-MIMO structure is first considered, and a novel transmission strategy is proposed by utilizing the joint instantaneous and statistical CSI. Specifically, a user scheduling scheme based on user locations is first presented. Subsequently, approximations of ergodic spectral efficiency (SE) are derived, serving as the basis of analog beamforming. Additionally, the signal processing at the local units and the central unit is carried out utilizing instantaneous CSI. Numerical results demonstrate that the proposed distributed XLMIMO structure and transmission strategy, leveraging angular division in a distributed manner, are capable of achieving SE comparable to that of a fully digital structure.