New design of SCM-SAC-OCDMA-FSO system by using gain techniqe based on MD code

الملخص EN

Free space optic (FSO) is a new modern communication system where free space acts as a medium between transverse and they should be in Line Of Sight (LOS) for successful transmission of optical beam.

Due to free space medium , it suffer of various interference like [Rain , Fog/Haze , Snow] that can effect on signal performance and lead to reduce the availability and reliability of the communication link .Because of Iraqi desert climate ,it exposed to dusty storm in most time of year more than other regions , so it is important to study the effect of Fog/Haze and find suitable method to reduce this atmospheric effect on the laser beam when it travel to its final point .Spectral Amplitude Coding Optical Code Division Multiple Access (SAC-OCDMA) has become a major area of research in optical communication system .

OCDMA allows multiple user to access the system without any contention; Multi Diagonal (MD) code used in system to support large number of user with high data rate .Optical amplifier is added to the system to provide more enhancement and permit to send the laser beam in longer distance and decrease the interference on it.

The result of the study shows that the performance of the proposed system is better than the system without amplifier.

It can be seen that the BER with minimum visibility (strong Haze storm) reach to 8 , BER of medium visibility between (1 & 8 ), BER with high visibility (1 ) at 1.85 Km as a transmission distance and 1Gbps as a transmission data.