3D massive MIMO channel model for high-speed railway wireless communication

In the fifth generation (5G) wireless communication, high-speed railway (HSR) communication is one of the most challenging scenarios. By adopting massive multi-input multi-output (mMIMO) technology in HSR communication, the design of the underlying communication system becomes more challenging. Some new channel characteristics must be studied, such as non-stationarity in space, time and frequency domains. In this paper, two models are established for the two states of HSR. When the HSR stops, a three-dimensional (3D) stationary channel model based on the single-ring distribution of the scatterers is established. When the HSR moves, a 3D non-stationary geometric random channel model(GRCM) based on the cylinder distribution of the scatterers by introducing the birth and death process of the propagation path and time-varying characteristics of the channel parameters is established. Moreover, a time evolution algorithm for time-varying channel parameters is proposed, and a modularization study of key parameter update algorithms is conducted. Finally, based on the proposed 3D non-stationary geometric random channel model, important time-varying channel statistical characteristics, such as time autocorrelation function (ACF), spatial cross-correlation function (CCF), doppler power spectral density (DPSD), and stationary interval are studied. Simulation results indicate that the properties of the proposed channel models, verified by simulation results, can match well with those of the theoretical model.

在第五代（5G）无线通信技术中，高速铁路（HSR）通信构成了最具挑战性的应用场景之一。通过在HSR通信中采纳大规模多输入多输出（mMIMO）技术，底层通信系统的设计面临更为严峻的挑战。必须研究一些新的信道特性，例如在空间、时间和频率域中的非平稳性。在本文中，针对HSR的两种状态建立了两种模型。当HSR静止时，基于散射体单环分布的三维（3D）平稳信道模型得以构建。而当HSR运行时，通过引入传播路径的出生与死亡过程以及信道参数的时间变异性，基于散射体圆柱分布的三维非平稳几何随机信道模型（GRCM）被建立。此外，针对时变信道参数，提出了一种时间演化算法，并对关键参数更新算法的模块化研究进行了探讨。最终，基于所提出的3D非平稳几何随机信道模型，研究了重要的时变信道统计特性，例如时间自相关函数（ACF）、空间互相关函数（CCF）、多普勒功率谱密度（DPSD）和稳定间隔。仿真结果表明，所提出的信道模型特性，经仿真验证，与理论模型相吻合。