Link Reliability Improvement for Optical Wireless Communication Systems With Temporal-Domain Diversity Reception

We experimentally demonstrate a simple temporal- domain diversity reception (TD-DR) scheme to enhance the reliability of optical wireless transmission links corrupted by atmospheric turbulence (AT) effects. Both nonreturn-to-zero and Manchester encoded on-off-keying modulation schemes are studied in laboratory environments at a 1.25-Gb/s data rate. AT effects are emulated as a slowly varying log-normal intensity variation for the received signal. System bit-error ratio is tracked for the performance evaluation, and results show that the outage probability due to the AT-induced intensity fluctuation for a 1.25-Gb/s link using Manchester coding is reduced from 3.2%plusmn0.1% to <0.1%, when the TD-DR is employed.