Multi-beam antenna systems are the basic technology used in developing fifth-generation (5G) mobile communication systems. In practical implementations of 5G networks, different approaches are used to enable a massive multiple-input-multiple-output (mMIMO) technique, including a grid of beams, zero-forcing, or eigen-based beamforming. All of these methods aim to ensure sufficient angular separation between multiple beams that serve different users. Therefore, ensuring the accurate performance evaluation of a realistic 5G network is essential. It is particularly crucial from the perspective of mMIMO implementation feasibility in given radio channel conditions at the stage of network planning and optimization before commercial deployment begins. This paper presents a novel approach to assessing the impact of a multi-beam antenna system on an intra-cell interference level in a downlink, which is important for the accurate modeling and efficient usage of mMIMO in 5G cells. The presented analysis is based on geometric channel models that allow the trajectories of propagation paths to be mapped and, as a result, the angular power distribution of received signals. A multi-elliptical propagation model (MPM) is used and compared with simulation results obtained for a statistical channel model developed by the 3rd Generation Partnership Project (3GPP). Transmission characteristics of propagation environments such as power delay profile and antenna beam patterns define the geometric structure of the MPM. These characteristics were adopted based on the 3GPP standard. The obtained results show the possibility of using the presented novel MPM-based approach to model the required minimum separation angle between co-channel beams under line-of-sight (LOS) and non-LOS conditions, which allows mMIMO performance in 5G cells to be assessed. This statement is justified because for 80% of simulated samples of intra-cell signal-to-interference ratio (SIR), the difference between results obtained by the MPM and commonly used 3GPP channel model was within 2 dB or less for LOS conditions. Additionally, the MPM only needs a single instance of simulation, whereas the 3GPP channel model requires a time-consuming and computational power-consuming Monte Carlo simulation method. Simulation results of intra-cell SIR obtained this way by the MPM approach can be the basis for spectral efficiency maximization in mMIMO cells in 5G systems.

中文翻译：

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大规模MIMO 5G宏小区的下行链路干扰处理

多波束天线系统是用于开发第五代（5G）移动通信系统的基本技术。在5G网络的实际实现中，使用不同的方法来实现大规模的多输入多输出（mMIMO）技术，包括波束网格，迫零或基于特征的波束形成。所有这些方法旨在确保为不同用户服务的多个光束之间有足够的角度间隔。因此，确保对现实的5G网络进行准确的性能评估至关重要。从mMIMO实施可行性的角度来看，在商业部署开始之前的网络规划和优化阶段，在给定的无线电信道条件下，实施mMIMO尤其重要。本文提出了一种新颖的方法来评估多波束天线系统对下行链路中的小区内干扰水平的影响，这对于5G小区中mMIMO的准确建模和有效使用非常重要。提出的分析基于几何通道模型，该几何通道模型允许绘制传播路径的轨迹，并因此绘制接收信号的角功率分布。使用多椭圆传播模型（MPM），并将其与由第三代合作伙伴计划（3GPP）开发的统计信道模型获得的仿真结果进行比较。传播环境的传输特性（例如功率延迟曲线和天线波束方向图）定义了MPM的几何结构。这些特性是根据3GPP标准采用的。获得的结果表明使用提出的新颖的基于MPM的方法对视线（LOS）和非LOS条件下的同信道波束之间所需的最小间隔角进行建模的可能性，这使得5G小区中的mMIMO性能达到被评估。该陈述之所以合理，是因为对于80％的小区内信噪比（SIR）模拟样本，对于LOS条件，MPM和常用3GPP信道模型获得的结果之间的差异在2 dB或更小范围内。此外，MPM仅需要单个仿真实例，而3GPP信道模型则需要耗时且计算量大的蒙特卡洛仿真方法。