BER Analysis of a Hybrid Modulation Scheme Based on PPM and MSK Subcarrier Intensity Modulation

Hongzhan Liu, Renbo Liao, Zhongchao Wei, Zhiyun Hou, Yaojun Qiao
2015 IEEE Photonics Journal  
In order to improve the bit-error-rate (BER) performance of free-space optical (FSO) communication systems employing binary phase-shift keying subcarrier intensity modulation (BPSK-SIM), an innovative hybrid modulation scheme called PPM-MSK-SIM is proposed, which is based on pulse position modulation (PPM) and minimum shift keying (MSK) subcarrier intensity modulation. Subsequently, the BER performance of PPM-MSK-SIM is studied in detail for an FSO system over log-normal turbulence channels
more » ... avalanche photodiode detection. The results of the numerical simulation show that PPM-MSK-SIM has the advantages of improving the BER performance compared with BPSK-SIM and PPM. For example, at the same received irradiance of À2.1 dBm and the same strength of turbulence C 2 n ¼ 7:5 Â 10 À15 m À2=3 , the BER performance of 2-PPM-MSK-SIM can decrease to 1:02 Â 10 À9 , whereas those of 2-PPM and BPSK-SIM are just 1:19 Â 10 À7 and 2:29 Â 10 À6 , respectively. This makes PPM-MSK-SIM a favorable candidate for the modulation technique in FSO communication systems. Index Terms: Free-space optical communication, subcarrier intensity modulation, atmospheric turbulence, atmospheric attenuation, bit-error rate (BER).
doi:10.1109/jphot.2015.2449265 fatcat:swp6ey22jbgdxoajaxuhbmi6om