Channel coding for 2-D FSO/CDMA systems over strong atmospheric turbulence channels

We propose 2-dimensional (2-D) free-space optical (FSO) CDMA system for broadband access networks. The performance of the proposed system is analyzed over strong atmospheric turbulence channels. To mitigate the impact of the strong atmospheric turbulence, channel coding schemes, including Reed-Solomon (R-S) and convolutional (CC) codes, are employed. In the analysis, we derive the upper bound of bit-error rate (BER) taking into account multiple access interference (MAI), optical beating interference (OBI) and receiver noise. It is shown that the channel coding schemes can help to effectively mitigate the impact of strong turbulence. Additionally, the use of channel coding enables the 2-D FSO/CDMA system to sustain from performance degradation when the supportable number of users increases.