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

TL;DR

This paper evaluates the uplink throughput of 5G NR UL-MIMO and UL-CA on a commercial network, revealing that UL-MIMO often underperforms except in strong RF conditions, where it can still be effective.

Contribution

It provides a real-world performance comparison of UL-MIMO and UL-CA on a commercial 5G network across various RF environments and transportation modes.

Findings

UL-MIMO often yields slower throughput than UL-CA in most scenarios.

UL-MIMO performs adequately in strong RF conditions.

UL-CA is more beneficial in weaker RF environments.

Abstract

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.