基于3D几何信道模型非对称波束信道特性分析

为了研究非对称波束模式对无线信道特性的影响,采用三维(3D)几何信道模型分析了宏蜂窝小区场景中非对称波束模式下的毫米波无线信道小尺度衰落特性。结合传播图理论提出一种非平稳3D几何信道建模方法,并通过生成的波束筛选出有效散射点,以期降低计算复杂度。分析了非对称波束模式对时域、频域、空域选择性衰落的影响。仿真结果表明,在宏蜂窝小区下行链路中,收发波束域交集中的有效散射点数量多于上行链路中的数量,导致其多普勒、时延、角度扩展明显高于上行链路,而上行链路则可近似为视距单径传播环境。

Channel Characterization of Nonreciprocal Beam Patterns Based on the 3D Geometric Channel Model

To investigate the influence of nonreciprocal beam patterns (NBP) on the wireless channel characteristics, a 3-dimensional (3D) geometric channel model is used to analyze the small-scale fading characteristics of the millimeter-wave wireless channel under this pattern in a macro-cell scenario. Specifically, a non-stationary 3D geometric channel modeling method is proposed based on the propagation graph theory. Moreover, by adopting transceiver beams, effective scatters are found out to reduce the computational complexity. According the proposed model, the influence of NBP on the selective fading characteristics involving time, frequency, and space domains are also analyzed. Simulation results reveal that the number of effective scatters located inside the intersection of downlink transceiver beams is larger than that of the uplink case, and thus the dispersion effects in Doppler, delay, and angular spreads of downlink transceiver beams are more serious than these of the uplink case. Besides, the latter case can be approximated as a line-of-sight scenario with a single propagation path.