高斯光束下的Gamma-Gamma分布模型研究

Study of Gamma-Gamma Model under Gaussian Beam

Gamma-Gamma模型是目前无线光通信中常用的光强闪烁模型。针对其参数模型较为复杂,各种近似模型的使用无参考依据的问题,在高斯光束下,通过仿真计算的方法,分别研究了波形条件、孔径尺寸、传输距离、内外尺度、湍流强度以及波长六方面因素对Gamma-Gamma模型的影响情况。结果表明:波形条件、孔径直径、传输距离、湍流强度对其影响都是不可忽略的,而内外尺度、近红外波段波长的影响则可以忽略不计;同时,只要孔径直径与传输距离的比值保持不变,则Gamma-Gamma模型分布特性不变。这些结论可为实际应用中模型的简化和无线光通信设备参数的设置提供参考和依据。

Gamma-Gamma model is a commonly used intensity scintillation model in wireless optical communications. For the problems of the complexity of the parameters models and the lack of reference for various approximate models, under Gaussian beam and using the method of simulation calculation, we analyze the effects of waveform condition, aperture dismeter, transmission distance, inner/outer scale, turbulent strength and wavelength on the characteristics of Gamma-Gamma model. The simulation results show that the effects of waveform condition, aperture diameter, transmission distance and turbulent strength cannot be ignored, while the effects of inner and outer scales, wavelength can be neglected. Moreover, as long as the ratio of aperture diameter to transmission distance remains unchanged, the Gamma-Gamma distribution characteristics will also keep unchanged. These conclusions provide reference and basis for the simplification of models in practical applications and the setting of system parameters for actual system.