Wide-Angle Lens Array Spatial Acquisition With Ultrawide Field of View in Optical Links Under Atmospheric Scintillation and Background Radiation

We propose a wide-angle lens array scheme, which can provide spatial acquisition with ultrawide field of view (FOV) in free-space optical (FSO) links. This acquisition array is composed of sub-arrays, with each subarray including receiving elements. The elements in a subarray are arranged in the same direction to receive the laser beacon together, while the subarrays are arranged in different directions to cover an ultrawide FOV (a hemisphere with a solid angle of ). The elements in a subarray can increase the total aperture size to restrict the laser power fluctuation induced by atmospheric scintillation. The subarrays can disperse the ultrawide FOV to reduce the received background power on each element. Therefore, the elements in a subarray and the subarrays can both contribute to the improvement of the SNR, which can improve the spatial acquisition performance of the wide-angle array. The missed detection probability (MDP), as a parameter to describe the spatial acquisition performance, is investigated for the wide-angle lens array spatial acquisition scheme under atmospheric scintillation and background radiation. Results show that the proposed array scheme can improve the spatial acquisition performance degraded by atmospheric scintillation and background radiation. The acquisition performance can be further enhanced with the increase of element number in a subarray and subarray number , where the elements in a subarray and the subarrays are designed to suppress atmospheric scintillation and background radiation, respectively.