Empirical Differences in LTE Open- and Closed-Loop Power Control
We present the empirical Physical Uplink Shared Channel radiated power of a User Equipment in a commercial Long-Term Evolution Frequency-Division Duplex system in open- and closed-Loop power control. We present new insights, targeted on power control, from the data taken by NASCTN Report-7, which presents measured radiated PUSCH channel power, while varying 28 different system factors. The NASCTN experiment was performed to examine the impact of each of the 28 factors on the radiated emissions of LTE UEs. Here, we address how the choice of power control algorithm impacts the radiated UE emissions. We examine the results of two cases: Reference Signals Received Power equal to -78 dBm and -98 dBm. We show significant differences in UE emissions using an open- or closed-loop power control algorithm in a stable RF environment. We discuss the difference in detail and note that the UE is not precisely following the power control equation as expected in all cases. This work is performed on a commonly used UE model in North America. The results can have implications for those looking to model or control 4G LTE UE emissions and designing accurate power control algorithms for emerging cellular systems such as 5G New Radio.
Empirical Differences in LTE Open- and Closed-Loop Power Control, IEEE Consumer Communications & Networking Conference, Online, CO, US, [online], https://doi.org/10.1109/CCNC49033.2022.9700612, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=933777
(Accessed August 18, 2022)