Analysis of Enhance Subcarrier Index Modulated MIMO-OFDM-FSO System

An enhanced subcarrier-index modulation (ESIM) based free space optical communication (FSO) system, which is superior to subcarrier-index modulation (SIM) and interleaved subcarrier-index modulation techniques (ISIM) is presented here. By incorporating orthogonal frequency division multiplexing (OFDM) and multi input multi output (MIMO) concept to enhanced subcarrier index modulation (ESIM), improved error rate is obtained than conventional SIM based OFDM systems. Further, ESIM-MIMO-OFDM-FSO system is implemented with simple transceiver structure having low detection complexity. ESIM-MIMO-OFDM-FSO system achieves better throughput than the existing optical OFDM system, since all subcarriers are used for data transmission. By utilizing the proposed ESIM-MIMO-OFDM- FSO system, simulation results clarify significant bit error rate (BER) and throughput improvement for different SNR values.