Several precise and computationally efficient results for pointing errors models in two asymptotic cases are derived in this paper. The normalized mean-squared error (NMSE) performance metric is employed to quantify the accuracy of different models. For the case that the beam width is relatively larger than the detection aperture, we propose the three kinds of models that have the form of $c_1\exp(-c_2r^2) $.It is shown that the modified intensity uniform model not only achieves a comparable accuracy with the best linearized model, but also is expressed in an elegant mathematical way when compared to the traditional Fraid model. This indicates that the modified intensity uniform model is preferable in the performance analysis of free space optical (FSO) systems that consider the effects of the pointing errors. By analogizing the beam spot with a point in the case that beam width is smaller than the detection aperture, the solution of the pointing errors model is transformed to a smooth function approximation problem, and we find that a more accurate approximation can be achieved by the proposed point approximation model when compared to the model that is induced from the Vasylyev model in some scenarios.
翻译:本文得出了两个零星案例的点误模型的精确和计算效率结果。 普通平均差( NMSE) 性能衡量标准用于量化不同模型的准确性。 对于光束宽度相对大于探测孔径的情况, 我们提出三种类型模型, 其形式为$c_ 1\exp(- c_ 2r/2美元) 。 显示经修改的强度统一模型不仅达到最佳线性模型的类似准确性, 而且与传统的Fraid 模型相比, 也以优雅的数学方式表示。 这表明在考虑点误效应的自由空间光学系统( FSO) 性能分析中, 修改的强度统一模型更为可取。 通过将光束点与比探测孔小的点进行模拟, 点误差模型的解决方案转换为平稳功能近似问题, 我们发现, 与一些情景中从Vasylev模型引出的模型相比, 可以通过拟议的点近似模型实现更准确的近似值。