Performance study of an enhanced fully optical generalized spatial modulation free-space optical system based on serial unmanned aerial vehicle relay

Abstract

This paper proposes an enhanced fully optical generalized spatial modulation (EFOGSM) free-space optical (FSO) system based on serial unmanned aerial vehicle (UAV) relaying under M distribution. The relay transmission mode of the system is decode-and-forward (DF), and two spatial diversity receiving schemes were considered at the receiver of the system. In the atmospheric channel modeling, the angle of arrival (AoA) jitter was introduced to represent the effect of UAV random jitter in the air on the channel, together with three important factors: path loss, pointing error, and atmospheric turbulence. Under the joint influence of the four fading factors, the probability density function expression of the joint fading channel under the new M distribution was derived, and the upper bound of the average bit error rate of the serial UAV-relaying EFOGSM FSO system was derived. The influence of key factors, such as the number of UAV relay nodes, the position distance of UAV, the field of view parameters of the receiver, the direction deviation, and the data transmission rate on the system performance, was analyzed by simulation under weak and strong turbulence. Monte Carlo simulation verified the correctness of the numerical calculation and simulation. This study provides a good theoretical basis for the engineering implementation of a serial UAV relay EFOGSM FSO system.