Hybrid pulse position modulation and binary phase shift keying subcarrier intensity modulation for free space optics in a weak and saturated turbulence channel

Monire Faridzadeh; Asghar Gholami; Zabih Ghassemlooy; Sujan Rajbhandari

doi:10.1364/JOSAA.29.001680

Hybrid pulse position modulation and binary phase shift keying subcarrier intensity modulation for free space optics in a weak and saturated turbulence channel

J Opt Soc Am A Opt Image Sci Vis. 2012 Aug 1;29(8):1680-5. doi: 10.1364/JOSAA.29.001680.

Authors

Monire Faridzadeh¹, Asghar Gholami, Zabih Ghassemlooy, Sujan Rajbhandari

Affiliation

¹ Department of Electrical and Computer Engineering, Isfahan University of Technology, Isfahan 84156-83111, Iran.

PMID: 23201885
DOI: 10.1364/JOSAA.29.001680

Abstract

In this paper a hybrid modulation scheme based on pulse position modulation (PPM) and binary phase shift keying subcarrier intensity modulation (BPSK-SIM) schemes for free-space optical communications is proposed. The analytical bit error rate (BER) performance is investigated in weak and saturated turbulence channels and results are verified with the simulation data. Results show that performance of PPM-BPSK-SIM is superior to BPSK-SIM in all turbulence regimes; however, it outperforms 2-PPM for the turbulence variance σ(1)(2)>0.2. PPM-BPSK-SIM offers a signal-to-noise ratio (SNR) gain of 50 dB in the saturation regime compared to BPSK at a BER of 10(-6). The SNR gain in comparison to PPM improves as the strength of the turbulence level increases.