Robust networked L₂-stable wireless SINR control

In the new radio wireless system, use cases for automation, automotive safety and virtual reality will require transmission and reception with very high reliability and very low latency. Radio channel fading and the onset of strong interference combine to make this task hard, which require new methods for mitigation. The alternative studied in this article is to introduce fast signal to interference and noise ratio (SINR) feedback control supported by feed-forward control from interference estimates, thereby improving the robustness of the networked loop. This challenging nonlinear networked control problem involves delay and coarse control signal quantization. To guarantee that the deployed feedback loop instances are always well-behaved, the SINR feedback controller is designed to be globally Script capital L-2-stable using a new loop gain-loop delay product condition, derived from the classical circle criterion. Monte-Carlo simulations show that the proposed controller is able to reduce the SINR back-off significantly.