Influence of Pointing Errors at the Block Error Rate Performance of Strong Turbulent SIMO FSO Links

The last few years Free Space Optical (FSO) communication has attracted significant research and commercial interest because of the many advantages in comparison with other wireless methods used for point-to- point connections. The operation of these systems strongly depends on the atmospheric and others effects in the area between the transmitter and the receiver. Among them, atmospheric turbulence and misalignment are two of the most significant performance mitigation factors. There have been proposed several methods and techniques in the literature in order to set against the induced fading of these phenomena. It is widely accepted that one of the most effective one is the employment of receivers’ diversity. Motivated by this and by taking into account that the ultra-fast modern optical communication systems are using blocks of bits for the transmission and codes for the detection and/or correction of the erroneous bits, in this work, we investigate the combined impact of pointing errors and strong turbulence in the total average block error rate (ABLER) of FSO systems with receivers’ diversity. Novel analytical expressions are derived using accurate approximations while the corresponding numerical results for realistic Single-Input Multiple-Output (SIMO) FSO links are presented.