Polarized pulse position modulation for wireless optical communications

Pulse Position Modulation (PPM) improves both the power efficiency and bit error rate (BER) performance compared with the On-Off Keying (OOK) in wireless optical communication. Polarization Shift Keying (PolSK) can prevent the negative effects of ambient light. However, they still suffer from short distance and low data rate especially in underwater environment. By combining PPM and PolSK schemes, we proposed a novel Polarized Pulse Position Modulation (P-PPM) scheme with two modes of full-rate or non-full-rate determined by a pattern selective ratio. Numerical results suggest that the new full-rate scheme improves the data rate, BER, and transmission distance compared with the PPM scheme with the same peak power, and also obtains an enhancement in power efficiency compared with the PolSK scheme. A proper pattern selective ratio is also determined to balance the data rate and BER performance.