Coherent optical binary polarisation shift keying heterodyne system in the free-space optical turbulence channel

Abstract

In this paper, analytical and simulation results for the bit error rate (BER) performance and fading penalty of a coherent optical binary polarization shift keying (2PolSK) heterodyne system adopted for a free space optical (FSO) communication link modeled as the log-normal and the negative exponential atmospheric turbulence channels are presented. The conditional and unconditional BER expressions are derived, demonstrating the comprehensive similarity between the 2PolSK and the binary frequency shift keying (2FSK) schemes with regards to the system sensitivity. The power penalty due to the non-ideal polarization beam splitter (PBS) is also analyzed. The receiver sensitivity employing 2PolSK is compared with other modulation schemes in the presence of turbulence and the phase noise. The results show that 2PolSK offers improved signal-to-noise ratio (SNR) performance compared to the binary amplitude shift keying (2ASK).

Simulated tornado optimization

“…This distribution for both kind of updates leads to more generality and acceptable performance respect to the uniform distribution. In addition, that is more general in dealing with different problems respect to the realistic atmospheric turbulence models like log-normal distribution utilized in the communication channel modeling [11]. Although, that is important to mention, according to our observations, log-normal distribution had shown some promisingly better performance than the normal distribution, at the case of unimodal problems.…”

Subcarrier Intensity Modulated Optical Wireless Communications Using Noncoherent and Differentially Coherent Modulations

“…The signal is used to modulate the transmitter laser after being properly biased. The transmitted power of the modulated laser beam, denoted by , can be written as (3) where is the average transmitting optical power, and is the modulation index satisfying the condition in order to avoid overmodulation.…”

“…Coherent optical polarization modulated system is another option which can provide improved link performance with increased system complexity. The performance of coherent binary and multilevel polarization-shift keying systems has been studied in [3] and [4]. Subcarrier intensity modulation is another attractive OWC technology.…”

Coherent Polarization Shift Keying Modulated Free Space Optical Links Over a Gamma-Gamma Turbulence Channel

“…However, the FSO link performance suffers from a number of phenomena such as the misalignment due to the building sway caused by the wind, thermal expansion and weak earthquakes (Uysal et al, 2006;Arnon, 2003;Tang et al, 2011). Another important issue with the outdoor FSO system is the susceptibility of the optical link to the atmospheric conditions.…”