基于几何的高速铁路协作MIMO信道建模

协作MIMO技术通过协作发射或协作接收的方式可以将干扰信号转变为有用信号，在高铁无线通信中引入该技术，能解决回波信道响应和提高系统容量。为了掌握协作MIMO技术在高铁场景中的信道特性，该文基于几何随机散射理论，提出一个高速铁路协作MIMO信道模型，简单调整该模型中的几个关键参数即可适用于高速铁路的多种场景。基于该模型计算信道冲激响应，推导多链路空间相关函数，进行数值计算、仿真分析和实测数据验证。仿真结果显示，直射分量越强，散射分量的角度扩展越小，多链路的空间相关性越强。散射次数越少，散射分量空间相关性越强。使用北京-天津高铁段LTE专网的实测数据验证理论模型的正确性。这些结论有助于认知协作MIMO信道和进行有效的测量活动。

Geometry-based Modeling for Cooperative MIMO Channel in High-speed Railway Scenarios

Cooperative MIMO technology can transform interference signals into useful signals by means of cooperative transmission or reception. It can solve the echo channel effect and improve the system capacity to be introduced into high-speed railway wireless communication. To master the channel characteristics of cooperative MIMO technology in high-speed railway scenarios, based on the geometric stochastic scattering theories, a new channel model for cooperative MIMO channel in high-speed railway scenarios is proposed, which can be applied to multiple high-speed railway scenarios by simply adjusting its several key parameters. Based on this model, the channel impulse response is calculated, the multi-link spatial correlation function is derived, the numerical calculation, simulation analysis and verification of measured data are carried out. Simulation results show that the multi-link spatial correlation is stronger when the LOS component is stronger and the angle spread of scattered components is smaller. The components which are scattered less times have a stronger spatial correlation. The theoretical model is verified by the measured data of the LTE special network of the Beijing-Tianjin high-speed railway section. These conclusions contribute to understanding the cooperative MIMO channels and conducting effective measurement activities.