Performance of Space Shift Keying over a Correlated Gamma-Gamma FSO-MISO Channel

In this paper, we present bit error rate (BER) analysis of space shift keying (SSK) for a free space optical multiple-input-single-output system over an arbitrarily correlated Gamma-Gamma (ΓΓ) channel for different correlation models under moderate and strong turbulence. We first derive the probability density function (pdf) of difference of two arbitrarily correlated ΓΓ random variables, and then derive a novel analytical expression for the average BER of the SSK scheme using the derived pdf. It is observed that the BER performance of the SSK scheme for considered system remains unaltered irrespective of the correlation model/level for ρ ≤ 0.795 and for ρ > 0.795, the BER performance improves.