On the Impact of Precoding Errors on Ultra-Reliable Communications

Abstract

Abstract.Motivated by the stringent reliability required by some of the future cellular use cases, we study the impact of precoding errors on the SINR outage performance for various spatial diversity techniques. The performance evaluation is carried out via system-level simulations, including the effects of multi-user and multicell interference, and following the 3GPP-defined simulation assumptions for a traditional macro case. It is shown that, except for feedback error probabilities larger than 1%, closed-loop microscopic diversity schemes are generally preferred over open-loop techniques as a way to achieve the SINR outage performance required for ultra-reliable communications. Macroscopic diversity, where multiple cells jointly serve the UE, provides additional robustness against precoding errors. For example, a 4x4 MIMO scheme with two orders of macroscopic diversity can achieve the 0 dB SINR outage target at the 10 −5 -th percentile, even for a precoding error probability of 1%. Based on the obtained results, it is discussed what transmission modes are more relevant depending on the feedback error constraint.

Real-time measurements and performance analysis of closed-loop MIMO service for mobile operators

“…System-level simulations are conducted in [13] with the specified aspects mostly affect the capacity and spectrum efficiency of LTE network which also includes CL MIMO. CL MIMO is shown to provide valuable signal-tointerference-plus-noise ratio (SINR) gains compared to OL MIMO via simulations even under Channel Status Information (CSI) feedback error scenarios in [14]. However both of these approaches ( [13,14]) are based on system level simulations that lack experimentation with real-world operational environments inside a MNO infrastructure.…”

“…CL MIMO is shown to provide valuable signal-tointerference-plus-noise ratio (SINR) gains compared to OL MIMO via simulations even under Channel Status Information (CSI) feedback error scenarios in [14]. However both of these approaches ( [13,14]) are based on system level simulations that lack experimentation with real-world operational environments inside a MNO infrastructure. There are also system-level studies for MIMO in the literature.…”