Analysis of Bit Rate vs SNR in Coded FSO Communication Systems

The main requirements for a future communication system are low complexity, stronger performance, data processing, and higher data rate. These requirements have been fulfilled by Free Space Optical (FSO) communication systems. FSO is a visible or wireless light communication (WLC) system. Performance analysis itself is a critical stage in the field of FSO/ wireless communications due to the nature of multi-path fading that is encountered due to scatters. The BER performance depends on the employed detection scheme, signal-to-noise ratio (SNR), and diversity order. The main basic components for selecting channel coding techniques are Bit Error Rate (BER) and SNR. This paper examined the performance of different channel coding schemes including convolutional coding, LDPC (low-density parity check) coding, TCM (trellis coded modulation) coding, and concatenated coding schemes during diverse turbulence conditions using the log-normal and gamma-gamma distribution model in MATLAB. Simulation results and performance evaluation in terms of bit rate indicated that the concatenated coding scheme outperforms the other single channel coding schemes under various turbulence conditions.