Abstract:
Optical wireless communication (OWC) over atmospheric
turbulence and pointing errors is a well-studied topic. Still,
there is limited research on signal fading due to random fog in an
outdoor environment for terrestrial wireless communications. In
this paper, we analyze the performance of a decode-and-forward
(DF) relaying under the combined effect of random fog, pointing
errors, and atmospheric turbulence with a negligible line-of-sight
(LOS) direct link. We consider a generalized model for the endto-
end channel with independent and not identically distributed
(i.ni.d.) pointing errors, random fog with Gamma distributed
attenuation coefficient, double generalized gamma (DGG) atmospheric
turbulence, and asymmetrical distance between the source
and destination. We develop density and distribution functions of
signal-to-noise ratio (SNR) under the combined effect of random
fog, pointing errors, and atmospheric turbulence (FPT) channel
and distribution function for the combined channel with random
fog and pointing errors (FP). Using the derived statistical results,
we present analytical expressions of the outage probability, average
SNR, ergodic rate, and average bit error rate (BER) for bothFPand
FPTchannels in terms ofOWCsystem parameters.We also develop
simplified and asymptotic performance analysis to provide insight
on the system behavior analytically under various practically relevant
scenarios. We demonstrate the mutual effects of channel
impairments and pointing errors on the OWC performance, and
show that the relaying system provides significant performance
improvement compared with the direct transmissions, especially
when pointing errors and fog becomes more pronounced.