Improve the bit error rate performance of free space optic due to atmospheric turbulence using new dual diffuser modulation

This paper focus on mitigating the atmospheric turbulence effect in free space optical communication using new dual diffuser modulation (DDM) technique. Phase screen diffuser located on transmitter create `new´ beam wave to propagate through turbulence more efficiently. This technique uses two transmitter and differential mode detection at the receiver. The result shows that for the receiving power performance at acceptable BER 10^-9 under the strong turbulence condition, the improvement of DDM technique approximately 99% and 66% if compare with Conventional intensity modulation for direct detection of On-off keying (CIM/DD-OOK) and Partially coherent beam On-off Keying (PCB-OOK). At 2.5 Gbps data bit rate the magnitude of BER for DDM technique increase with 12 magnitudes or equivalent to 100% improvement and the CIM/DD-OOK with diffuser only 2 magnitudes which give the 33% improvement.