Evaluation of the performance of FSO system using OOK and M-PPM modulation schemes in inter-satellite links with turbo codes

This paper gives a detailed overview of the inter-satellite links used in free space optical (FSO) communication. FSO communication uses laser technology to send and receive data. For the modulation of message signal, OOK and 8-PPM schemes are used. As energy in the inter-satellite link is a major constraint, OOK and M-PPM provide better options than others since they have to remain ON for the transmission of bit `1´ only. In this paper, turbo code is used for improving the system performance. Turbo code adds redundancy to the input block code. Therefore, it minimizes the average weight of the code and reduces the data rate. At the same time, it lowers the probability of error. Overall performance of the system improves significantly as evident from the computed results.