A 3D Continuous-Space Electromagnetic Channel Model for 6G Tri-Polarized Multi-user Communications
Yue Yang, Cheng-Xiang Wang, Jie Huang, John Thompson, H. Vincent Poor
TL;DR
The paper introduces a 3D continuous-space electromagnetic channel model for tri-polarized multi-user 6G systems, integrating near-field spherical wavefronts and rich scattering. It links transmitter currents to received fields via the dyadic Green's function and decomposes the radiation operator using spherical wave functions, enabling a SVD-based representation and an efficient current optimization. Statistical properties and channel capacities for both single- and multi-user scenarios are derived, and the model is validated against full-wave simulations to show that scatterers, larger apertures, and finer sampling can markedly increase DoF and capacity. The findings highlight practical implications for antenna design, channel estimation, and precoding in future 6G networks, especially under near-field and scattering-rich environments.
Abstract
It is envisioned that the sixth generation (6G) and beyond 6G (B6G) wireless communication networks will enable global coverage in space, air, ground, and sea. In this case, both base stations and users can be mobile and will tend to move continuously in three-dimensional (3D) space. Therefore, obtaining channel state information (CSI) in 3D continuous-space is crucial for the design and performance evaluation of future 6G and B6G wireless systems. On the other hand, new 6G technologies such as integrated sensing and communications (ISAC) will also require prior knowledge of CSI in 3D continuous-space. In this paper, a 3D continuous-space electromagnetic channel model is proposed for tri-polarized multi-user communications, taking into account scatterers and spherical wavefronts. Scattered fields are calculated using the method of moments (MoM) with high accuracy. Spherical wave functions are utilized to decompose the dyadic Green's functions that connect the transmitted source currents and the received electric fields. Simulation results demonstrate that transmit power, apertures, scatterers, and sample intervals have significant impacts on statistical properties and channel capacities, providing insights into the performance of continuous-space electromagnetic channel models and the design of future wireless systems.