er processing within fronthaul bandwidth limitations. Eight cross-polarized beams are assumed for Option 7-2a. The simulations indicate that Option 7-3 gives better performance than Option 7-2a in all cases, and the differences range from 1% to 4%. The smallest difference between the two options is with 4 RXs, 16 TRXs, and 3 km/h while the largest difference is with 8 RXs, 64 TRXs, and 60 km/h. The benefits of Option 7-3 are greatest when a larger number of inputs to the IRC receiver are used, when a larger number of TRXs is available, and when the UE speed is high. On the other hand, Option 7-2a allows the use of more 10.7 Massive MIMO and Beamforming Algorithms Uplink user throughput kbps 2000 7-2a 7-3 7-2a 7-3 7-2a 7-3 7-2a 7-3 7-2a 7-3 7-2a 7-3 7-2a 7-3 7-2a 7-3 3 km/h 60 km/h 3 km/h 60 km/h 3 km/h 60 km/h 3 km/h 60 km/h 16TRX 64TRX Figure 10.44 Uplink user throughput with different architecture options. advanced receivers at the baseband module with higher processing capabilities. Option 7-2a also allows the realization of more gains from distributed MIMO when compared to 7-3 (Table 10.17). 10.7.4 RF Solution Benchmarking Massive MIMO provides the most advanced radio performance, but it may not fit into all sites from the size or power consumption point of view. A multiband passive antenna with separate 4TRX or 8TRX RF heads may be an alternative solution. Table 10.18 illustrates high level benchmarking of 64TRX and 16TRX massive MIMO solutions and Table 10.18 Benchmarking of different RF solutions for 3.5 GHz. Massive Massive Passive Passive antenna antenna 64TRX 16TRX Coverage gain in 9 dBa) uplink VS. 2RX and 17 dBi antenna Capacity gain in downlink VS. 2TRX 77 dBm with 74 dBm with 74 dBm with 71 dBm with 200 W 100 W 8 X 30 W 4 X 40 W Multiband support Hybrid antenna Hybrid antenna a) 7 dB antenna gain and 2 dB lower losses. b) 4 dB diversity gain and 2 dB antenna gain (19 dBi). c) 2 dB antenna gain and 2 dB antenna gain (19 dBi). 10 5G Performance 8TRX and 4TRX RF head solutions with a passive antenna at