基于MIMO的对流层散射通信信道损耗研究

针对多输入多输出(Multiple-Input Multiple-Output,MIMO)场景下的对流层散射通信信道损耗进行了研究。在设计远距离MIMO通信系统时,链路损耗估计是其中的关键技术,而现有技术在损耗估计时都忽略了波束与散射体碰撞时的能量损耗。根据湍流非相干散射理论,首先将对流层建模为多条可微的曲线,从而与发射和接收天线阵列构成曲边梯形,根据此信道几何模型,计算入射角、反射角和散射角的角度关系；其次,建立了电磁波束射入散射体后散射波在散射体表面的能量分布模型；最后,根据波束传输距离,量化散射信道的损耗,推导得到基于MIMO对流层散射信道的衰落系数和信道矩阵。将仿真计算结果与实际数据进行对比,验证了所提模型在链路损耗估计问题上的有效性和准确性,同时根据仿真结果对接收天线的仰角设计提出了建议。

Research on Channel Loss of Tropospheric Scatter Communication Based on MIMO

The channel loss of the tropospheric scatter communication in Multiple-Input Multiple-Output (MIMO) scenarios was studied in this paper.When designing a long distance MIMO communication system,one of the key technologies is the estimation of link loss,but all of existing technologies ignore the energy loss of collisions between beam and scatterers when estimating loss.According to the theory of turbulent incoherent scattering,firstly,we modeled troposphere as many differentiable curves,so that it can constitute curved trapezoid together with transmit and receive antenna array.And then we calculated the angular relation of angle of incidence,angle of reflection and scattering angle on the basis of this geometric channel model.Secondly,we established the energy distribution model of the scattered wave on the surface of scatterers after electromagnetic beam injection.Finally,according to the propagation distance of beam,we quantified the scattering channel loss,and derived the fading coefficients and channel matrix.By comparing simulation results with the actual data,we verified validity and accuracy of the proposed model on the problem of estimation of link loss,meanwhile gave suggestions for the design on elevation angle of receive antenna according to the simulation results.