Performance Comparison of 5G NR Uplink MIMO and Uplink Carrier Aggregations on Commercial Network

Demands for uplink on mobile networks are increasing with the rapid development of social media platforms, 4K/8K content creation, IoT applications, and Fixed Wireless Access (FWA) broadband. As a result, Uplink MIMO (UL-MIMO) and Uplink Carrier Aggregation (UL-CA) have been widely deployed for the first time on commercial 5G networks. UL-MIMO enables the transmission of two data streams on one frequency band in strong RF conditions, theoretically doubling throughput and efficiency. On the other hand, UL-CA allows for simultaneous upload on greater channel widths, allowing more resources to be assigned to a single UE for higher throughput. In the United States, T-Mobile USA, a mobile network operator (MNO), has deployed network-wide 5G Standalone (SA), along with UL-MIMO on Time Division Duplex (TDD) band n41 and UL-CA between TDD and Frequency Division Duplex (FDD) NR bands. In this paper, the uplink throughput performance of UL-MIMO and UL-CA will be evaluated on the commercial T-Mobile 5G network on a variety of RF environments and modes of transportation. It was found that, even with the efficiency gains, UL-MIMO yields slower uplink throughput in most scenarios. However, in stronger RF conditions, UL-MIMO can provide an adequate user experience, so capacity can be conserved by reserving UL-CA for UE in weaker RF conditions.