Adaptive calibration improves radio signal mapping with fewer measurements
Adaptive Calibration of RF Digital Twins via Budget-Constrained Radio Measurement Selection
Networking and Internet Architecture
Summary
Wireless signals change depending on where you measure them, and building easy-to-use models to predict these signals can be tricky because the environment is complex. The authors created a system that uses maps and 3D models to simulate how signals travel but found the simulation needs correction based on some real measurements. They figured out smart ways to choose where to take these measurements to fix the model efficiently without using too many resources. Their method especially helps when only a small number of measurements can be made.
What this means in practice
- •For wireless network planners: Improve prediction of signal strength in urban areas by efficiently calibrating radio models with limited measurement data.
- •For smart city infrastructure teams: Use adaptive measurement selection to calibrate digital twins for better management of wireless coverage and connectivity in city environments.
Authors
Yalin E. Sagduyu, Tugba Erpek, Hossein Jafari
Abstract
Radio-frequency (RF) digital twins (DTs) enable site-specific wireless propagation prediction by explicitly reconstructing the physical environment and modeling electromagnetic interactions. Although physics-based DTs reduce reliance on exhaustive measurements, systematic bias relative to real radio data arises from environmental uncertainty, material inaccuracies, and geometric abstractions. Calibration using field measurements is therefore necessary but costly under limited sampling budgets. This paper studies active RF DT calibration, in which measurement locations are selected sequentially and in an online manner to estimate a calibration offset under strict measurement budget constraints. A physics-based RF DT pipeline is developed, integrating semantic geospatial data from OpenStreetMap, 3D modeling in Blender, and deterministic ray tracing in Sionna to capture dominant building and foliage effects. This RF DT is calibrated using path-loss measurements collected with software-defined radios. Multiple online calibration strategies that select radio measurement locations are compared, including random sampling, rank-structured sampling with balanced coverage, quasi-Monte Carlo ranked selection, progressive structure-aware allocation, and fully adaptive uncertainty-driven sampling with estimator stabilization. Results demonstrate that adaptive and structure-aware schemes significantly improve both mean and worst-case calibration accuracy, particularly in the low-budget regime for radio measurements.