Research on Modulations of Wireless Optical Communication System Based on RS Code under Weak Turbulence Atmosphere Channel

Abstract

The free space optical (FSO) system model is analyzed based on on-off keying (OOK), pulse position modulation (PPM), differential pulse position modulation (DPPM) and digital pulse interval modulation (DPIM) under the weak turbulence atmosphere. To improve the system performance, one effective way is to use forward error correction (FEC).The bit error rate (BER) calculating formula of uncoded system is derived under all above the modulations firstly, then as a benchmark, under the case of independent with identical distribution, the average bit error rates of RS coded system are derived, respectively. Simulations of the average bit error rate performance of these systems are done. Simulation results show that, PPM has the best bit error rate performance, RS coded is efficient to get the code gain and to improve jamming-rejection capability of system.

Research on underwater optical communication technology based on RS coding and OFDM

“…RS code is a linear block cyclic code with superior performance in forward error correction coding. Compared with other linear block codes, it has the highest error correction ability and coding efficiency, and has strong correction to random errors and burst errors [6] . When light propagates in seawater channel, it is attenuated by absorption and scattering, and the signal quality becomes worse and worse with the increase of transmission distance.…”