Turbulence channel modeling and non-parametric estimation for optical wireless scattering communication

Abstract

We adopt mixed Poisson distribution to characterize the channel turbulence for the optical wireless scattering communication. The expectation-maximization (EM) algorithm is applied to estimate each component of the mixed Poisson distribution. We analyze the temporal correlation of the turbulence-induced fading, which is crucial for designing the frame length and the training signal pattern for channel estimation. Computer simulations show the good performance of the proposed estimation approaches for the mixed Poisson distribution and the temporal correlation. Results based on the outdoor experimental data with the transceiver distance of 1500 meters are also presented. It is shown that the coherent time length can reach the order of several hundred milliseconds.