A Non-Stationary 3-D Wideband Twin-Cluster Model for 5G Massive MIMO Channels

TLDR

Near‑field effects, rather than far‑field approximations, must be considered for massive MIMO antenna arrays. The paper introduces a novel non‑stationary 3‑D wideband twin‑cluster channel model for massive MIMO systems operating at gigahertz frequencies. The model employs spherical wavefronts and a birth‑death process to capture cluster appearance and disappearance across array and time dimensions, and evaluates its statistical impact through correlation functions, condition numbers, angular power spectra, and elevation‑angle effects, with a corresponding simulation framework. Numerical results demonstrate that the model provides a viable design framework for massive MIMO channel modeling.

Abstract

This paper proposes a novel theoretical non-stationary three dimensional (3-D) wideband twin-cluster channel model for massive multiple-input multiple-output (MIMO) communication systems with carrier frequencies on the order of gigahertz (GHz). As the dimension of antenna arrays cannot be ignored for massive MIMO, near field effects instead of far field effects are considered in the proposed model. These include the spherical wavefront assumption and a birth-death process to model non-stationary properties of clusters such as cluster appearance and disappearance on both the array and time axes. Their impacts on massive MIMO channels are investigated via statistical properties including correlation functions, condition numbers, and angular power spectra. Additionally, the impact of elevation angles on correlation functions is discussed. A corresponding simulation model for the theoretical model is also proposed. Finally, numerical analysis shows that the proposed channel models are able to serve as a design framework for massive MIMO channel modeling.