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CommUNext: Deep Learning-Based Cross-Band and Multi-Directional Signal Prediction

Chi-Jui Sung, Fan-Hao Lin, Tzu-Hao Huang, Chu-Hsiang Huang, Hui Chen, Chao-Kai Wen, Henk Wymeersch

TL;DR

6G networks require cross-band cognition across FR1–FR3, but physics-based ray tracing and inter-frequency measurement gaps impede scalable planning and operation. CommUNext presents a data-driven framework that predicts high-frequency ($7$ GHz), multi-directional signal-strength maps from low-frequency coverage maps and sparse high-frequency measurements, formalized via a Bayes-optimal predictor $f^*(\mathcal{X})=\mathbb{E}[\mathcal{Y}|\mathcal{X}]$. It introduces Full CommUNext and Partial CommUNext to handle complete and incomplete reference-band data, respectively, leveraging an automated data-generation pipeline (OSM/Blender/Sionna) to produce aligned $128\times128$ maps and LoS/NLoS priors. Across extensive RT-based experiments, the Seg architecture improves accuracy, Partial CommUNext demonstrates robust reconstruction under incomplete coverage with tunable sampling strategies, and the approach promises scalable, real-time cross-band beam prediction and resource management for 6G deployments.

Abstract

Sixth-generation (6G) networks are envisioned to achieve full-band cognition by jointly utilizing spectrum resources from Frequency Range~1 (FR1) to Frequency Range~3 (FR3, 7--24\,GHz). Realizing this vision faces two challenges. First, physics-based ray tracing (RT), the standard tool for network planning and coverage modeling, becomes computationally prohibitive for multi-band and multi-directional analysis over large areas. Second, current 5G systems rely on inter-frequency measurement gaps for carrier aggregation and beam management, which reduce throughput, increase latency, and scale poorly as bands and beams proliferate. These limitations motivate a data-driven approach to infer high-frequency characteristics from low-frequency observations. This work proposes CommUNext, a unified deep learning framework for cross-band, multi-directional signal strength (SS) prediction. The framework leverages low-frequency coverage data and crowd-aided partial measurements at the target band to generate high-fidelity FR3 predictions. Two complementary architectures are introduced: Full CommUNext, which substitutes costly RT simulations for large-scale offline modeling, and Partial CommUNext, which reconstructs incomplete low-frequency maps to mitigate measurement gaps in real-time operation. Experimental results show that CommUNext delivers accurate and robust high-frequency SS prediction even with sparse supervision, substantially reducing both simulation and measurement overhead.

CommUNext: Deep Learning-Based Cross-Band and Multi-Directional Signal Prediction

TL;DR

6G networks require cross-band cognition across FR1–FR3, but physics-based ray tracing and inter-frequency measurement gaps impede scalable planning and operation. CommUNext presents a data-driven framework that predicts high-frequency ( GHz), multi-directional signal-strength maps from low-frequency coverage maps and sparse high-frequency measurements, formalized via a Bayes-optimal predictor . It introduces Full CommUNext and Partial CommUNext to handle complete and incomplete reference-band data, respectively, leveraging an automated data-generation pipeline (OSM/Blender/Sionna) to produce aligned maps and LoS/NLoS priors. Across extensive RT-based experiments, the Seg architecture improves accuracy, Partial CommUNext demonstrates robust reconstruction under incomplete coverage with tunable sampling strategies, and the approach promises scalable, real-time cross-band beam prediction and resource management for 6G deployments.

Abstract

Sixth-generation (6G) networks are envisioned to achieve full-band cognition by jointly utilizing spectrum resources from Frequency Range~1 (FR1) to Frequency Range~3 (FR3, 7--24\,GHz). Realizing this vision faces two challenges. First, physics-based ray tracing (RT), the standard tool for network planning and coverage modeling, becomes computationally prohibitive for multi-band and multi-directional analysis over large areas. Second, current 5G systems rely on inter-frequency measurement gaps for carrier aggregation and beam management, which reduce throughput, increase latency, and scale poorly as bands and beams proliferate. These limitations motivate a data-driven approach to infer high-frequency characteristics from low-frequency observations. This work proposes CommUNext, a unified deep learning framework for cross-band, multi-directional signal strength (SS) prediction. The framework leverages low-frequency coverage data and crowd-aided partial measurements at the target band to generate high-fidelity FR3 predictions. Two complementary architectures are introduced: Full CommUNext, which substitutes costly RT simulations for large-scale offline modeling, and Partial CommUNext, which reconstructs incomplete low-frequency maps to mitigate measurement gaps in real-time operation. Experimental results show that CommUNext delivers accurate and robust high-frequency SS prediction even with sparse supervision, substantially reducing both simulation and measurement overhead.

Paper Structure

This paper contains 29 sections, 2 theorems, 17 equations, 11 figures, 6 tables.

Key Result

Theorem 1

Under the MSE criterion, the Bayes-optimal predictor of $\mathcal{Y}$ given $\mathcal{X}$ is

Figures (11)

  • Figure 1: Automated data generation toolchain integrating OSM, Blender, and Sionna.
  • Figure 2: Example of importing OSM building data into Blender.
  • Figure 3: Example of (a) a building map $\mathbf{B}$ and (b) the corresponding 3.5 GHz coverage map $\mathbf{S}_c$.
  • Figure 4: Eight generated 7 GHz SS maps $\{\mathbf{S}_{d1}, \mathbf{S}_{d2}, \dots, \mathbf{S}_{d8}\}$, showing beam concentration along pointing directions and variations caused by blockages.
  • Figure 5: (a) LoS and (b) NLoS masks corresponding to the building map in Fig. \ref{['fig:building_coverage']}(a).
  • ...and 6 more figures

Theorems & Definitions (3)

  • Theorem 1: Bayes-Optimal Predictor under MSE bishop2006pattern
  • Corollary 1: Incomplete Reference-Band Case
  • Remark 1: Structured Prior via NLoS Mask