Radio access network splits for reduced radio unit complexity

Abstract

The technology described herein is directed towards radio unit and distributed unit splits, including for massive MIMO systems and/or O-RAN splits. Demodulation reference signal (DMRS)-based receive beamforming is split between a radio unit and a distributed unit, in which the computational resources needed for channel estimation, DMRS weight calculation and equalization are located in the distributed unit rather than the radio unit. In one implementation, the radio unit extracts the DMRS symbols and resource elements (REs) and sends them with little or no beamforming to the distributed unit; channel estimation and beamforming coefficients are computed at the distributed unit based on the DMRS data, and returned to the radio unit for use in receive beamforming for the current slot or a future slot. The radio unit can send candidate beams to the distributed unit for combining to reduce any non-optimality of the beams. A future optimal beam can be predicted.