BER Performance Comparison of Coded Communication Systems under Different Turbulence Coditions of Free Space Optical Channel

Abstract

The congestion and the limitations on bandwidths of the radio spectrum have posed a constraint for the growth of radio wireless systems. Wireless optical communication, also known as free space optical communication (FSO), is believed to be a long-term option for many wireless communication applications. Atmospheric turbulence is generally considered to be multiplicative noise source that reduces the capability of receiver to estimate the information contained in the modulated optical wave. This paper gives a comparative study of the behavior of the turbo/LDPC/convolutional-coded FSO system under different turbulence conditions. From the simulation results, it is clear that the turbo codes and LDPC codes are most suitable schemes for handling all the three cases of turbulences. They also provide a very good coding gain resulting in very low SNR requirements.

Keywords: Free space optics, FSO channel, turbulence, turbo code, LDPC code