can be improved. If more processing is located in the baseband Dis- tributed Unit (DU), the virtualization benefits are higher, and the complexity of the distributed unit is lower. This section compares the different uplink algorithms reflecting different functionality splits. The benchmarking focuses on Options 7-2a and 7-3. Option 7-3 has more processing in the remote unit, while Option 7-2a has more processing in the centralized unit. The main differences between these two options are listed below: 10 5G Performance Downlink Uplink Figure 10.43 Functionality split options between centralized and Baseband distributed unit (DU) remote radio units. Option 6 Coding Decoding Option 7-3 Modulation Demodulation Option 7-2 Precoding Channel estimation Option 7-2a Beamforming Beamforming Option 7-1 Radio unit (RU) Option 7-2a Best beams information for multi-user pairing and receiver processing is done either through wideband SRS (TDD) or from the UE feedback (TDD or FDD). Only beam space signals corresponding to the N best beams are made available (post digital beamforming) for channel estimation and further baseband processing. Option 7-3 N best beams for receiver processing are computed using reference signals over the allocated resource blocks for each UE. Best beams information for multiuser pairing is done either through wideband SRS (TDD) or from the UE feedback (TDD or FDD). Beamspace signals corresponding to all the beams are made available for channel esti- mation. Only the signals corresponding to the N beams are made available for further base- band processing. Figure 10.44 shows uplink user throughputs with Options 7-2a and 7-3. The results are shown for 4RX IRC and 8RX IRC for both the 16TRX and 64TRX cases. 10 UEs per cell is assumed in the simulations with 10 MHz bandwidth. Option 7-3 uses SRS-based wideband beam selection for UE pairing and Demodulation Reference Signal (DMRS)-based beam selection for receiver processing. Option 7-2a uses SRS-based wideband beam selection for both UE pairing and receiv