  Free Space Optics systems (FSO) is one of the evolving wireless technologies.
FSO is the only technology with highest data rates in wireless mode of
operation but it suffers from bad weather conditions. In this work, analysis is
carried out on FSO system having certain parameters constant using different
modulation formats (i.e. RZ, NRZ, MDRZ, MODB and CSRZ). Impact of data rate,
link range, input power and attenuation factor has been computed. Weather
conditions are supposed to be nearly clear and suitable for FSO communication
while taking attenuation factor up to 10dB/Km. Q-factor, received signal power
and BER is calculated in all scenarios for obtaining an estimate of system
performance. Results have shown that NRZ & RZ formats are in the lead until now
with highest Q values.
