Integrated Sensing and Communication for 6G Holographic Digital Twins

TL;DR

The paper tackles building high-fidelity holographic digital twins in 6G by fusing sensing and communication through an ISAC-based four-layer architecture, targeting KPIs such as a peak data rate of $1\ \mathrm{Tbps}$ and end-to-end latency of $0.1$ ms with high reliability ($10^{-9}$ BER). It defines the four-layer framework (Physical, Digital Twin, Intelligence, and Holographic Interaction) and outlines super-resolution approaches at the physical and intelligence layers to raise HDT resolution. It investigates cooperative sensing strategies—node selection, multi-band collaboration, cooperative beamforming, and data fusion—and provides simulations showing gains in distance estimation accuracy and spectral efficiency with multi-node cooperation. The work points to future directions including ambient intelligence, over-the-air computation, and semantic communication with Large Language Models to further improve HDT data acquisition and transmission.

Abstract

With the advent of 6G networks, offering ultra-high bandwidth and ultra-low latency, coupled with the enhancement of terminal device resolutions, holographic communication is gradually becoming a reality. Holographic digital twin (HDT) is considered one of key applications of holographic communication, capable of creating virtual replicas for real-time mapping and prediction of physical entity states, and performing three-dimensional reproduction of spatial information. In this context, integrated sensing and communication (ISAC) is expected to be a crucial pathway for providing data sources to HDT. This paper proposes a four-layer architecture assisted by ISAC for HDT, integrating emerging paradigms and key technologies to achieve low-cost, high-precision environmental data collection for constructing HDT. Specifically, to enhance sensing resolution, we explore super-resolution techniques from the perspectives of parameter estimation and point cloud construction. Additionally, we focus on multi-point collaborative sensing for constructing HDT, and provide a comprehensive review of four key techniques: node selection, multi-band collaboration, cooperative beamforming, and data fusion. Finally, we highlight several interesting research directions to guide and inspire future work.

Figures (6)

• Figure 1: Application Scenarios of ISAC-Assisted HDT.
• Figure 2: The Four-Layer Architecture of ISAC-Assisted HDT.
• Figure 3: Super-resolution for HDT construction assisted by ISAC.
• Figure 4: Perspectives of cooperative sensing technology for constructing HDT.
• Figure 5: Performance improvement of S&C in multi-node collaboration.