Optical Space Time Pulse Position Modulation over Exponential Weibull Turbulence Channel

An optical space time pulse position modulation (OSTPPM) scheme is proposed to satisfy the communication requirement of high transmission rate and better reliability. For the OSTPPM scheme, an improved threshold judgment-based orthogonal matching pursuit (IT-OMP) algorithm with low-complexity and near optimal performance is proposed. The average bit error rate of OSTPPM-IT-OMP scheme is investigated over the exponential Weibull channel, and its analytical expression is verified via Monte Carlo simulation. With the same simulation parameters, the signal to noise ratio of (4,4,2)-OSTPPM-IT-OMP is respectively 3.75 dB and 8.5 dB better than that of spatial pulse position modulation (SPPM) scheme and generalized spatial pulse position modulation (GSPPM) scheme at a bit error rate of 1 × 10⁻³. With the same transmission bits per symbol, the computational complexity of (3,4,2)-OSTPPM-IT-OMP scheme is reduced by 90.47% and 75.4% compared with (16,4,2)-SPPM and (5,4,2)-GSPPM schemes, respectively.