• Mohammad Yawar wani
• Dr Karamjit Kaur
• Dr Priti Singh

Free space Optical (FS0) communication has been emerged as a more conventional means of communication rather than the traditional optical communication. Performance of FSO communication system depends upon number of parameters. These parameters can be divided into two categories such as (i) internal parameters (ii) external parameters. Internal parameters are concerned with design of FSO system and include wavelength, optical power, transmission bandwidth, divergence angle and optical loss on the transmitter and bit error rate (BER), receiver lens diameter, and receive field of view (FOV) on the receiver. External parameters are linked with environment such as visibility, atmospheric attenuation, scintillation etc. which come under the effects of atmospheric conditions. There are a number of techniques to take the edge off these channel effects such as selection of an efficient modulation scheme, aperture averaging, receiver diversity, diversity (in space, time or frequency), coding, adaptive optics etc. The keen focus of our paper will be on effective modulation for FSO system. We will discuss various modulation schemes associated with FSO systems.

Bit error rate , Free space optics, ON OFF Keying, Quadrature amplitude modulation

"COMPARISION IN MODULATION TECHNIQUES FOR FSO COMMUNICATION SYSTEM.", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.5, Issue 6, page no.40-42, June-2018, Available :http://www.jetir.org/papers/JETIR1806248.pdf

"COMPARISION IN MODULATION TECHNIQUES FOR FSO COMMUNICATION SYSTEM.", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.5, Issue 6, page no. pp40-42, June-2018, Available at : http://www.jetir.org/papers/JETIR1806248.pdf