BER performance improvement with combination of OVSF spreading and convolution code in inter satellite links using FSO

Free-space optical communications is an emerging solution to enhance the capacity and security of inter satellite links to gigabits per second. It is widely believed to overcome data rate limitations in such links as the quantity of data gathered goes on mounting. This paper discusses the application of a combination of error control coding scheme and spreading to the inter-satellite free space optic link. For the intensity modulation/ direct detection scheme, BER performance improvement by the use of convolution coding, due to spreading operation using orthogonal vector spreading factor (OVSF) codes as pseudorandom sequence is discussed followed by suggesting a combination of both codes. The simulation results are presented for single input single output (SISO) systems.