The Influence Factors And Performance Analysis Of Wireless Optical Communication Systems

Wireless Optical Communication (Free Space Optical Communication-FSO) has many advantages, such as good security, effective anti-interference, high data transfer rate, flexibility and convenience and so on. So it is an available mean to solve"the last mile problem"and emergence communication. The influence of characteristics of atmospheric on the performance of Wireless Optical Communication systems is currently the key problem for the exploitation of the laser communication systems in civil and military application.Laser transmitting through the atmosphere, the attenuation characteristics of aerosols, rain, fog and snow and the turbulence scintillation are analyzed. The BER and SNR caused by the laser transmitted attenuation of rain, fog and snow are calculated. The BER and SNR caused by atmosphere turbulence scintillation and improved by more apertures transmitted technique are analyzed. The influences of BER using different modulation techniques in the weak and strong fluctuation regimes on Wireless Optical Communication systems are discussed. The results show that the subcarrier BPSK modulation is superior to the OOK and subcarrier DPSK modulations in Wireless Optical Communication systems applications. The performance of Wireless Optical Communication systems improved by using a partially coherent source beam, more apertures transmitted technique and the subcarrier modulation technique is calculated. The BER can be significantly reduced by means of using a partially coherent source beam, so the performance is improved. On the other hand, more apertures transmitted technique can weaken atmosphere scintillation effects, and improve communication quality. Using more apertures transmitted technique and subcarrier modulation technique can also improve the communication systems performance further. Therefore, the optical communication systems performance in atmosphere optical channels can be improved by means of using a larger correlation parameter partially coherent laser beam source, more apertures transmitted technique, or appropriate modulation and demodulation. These studies have great academic and practical values in the development and application of wireless optical communication systems.