Diversity Gain and Outage Probability for MIMO Free-Space Optical Links with Misalignment

Free-Space Optical Communications: Capacity Bounds, Approximations, and a New Sphere-Packing Perspective

“…Simple capacity expressions are of theoretical importance since they can be used to study fading channels [24], [27]. From this point of view, it is interesting to find simple fitting functions which capture the best known achievable rate R F given in [12].…”

“…A closed-form expression is important for the study of practical systems under fading scenarios. The availability of such an expression allows a better understanding of the ultimate performance of IM-DD systems beyond simple sub-optimal schemes such as on-off keying [2], [3], [21] or binary pulse-position modulation [22], [23], and beyond high SNR scenarios with only an average constraint [24]. To make the capacity approaching scheme in [12] more accessible, we provide a simple fitting function which closely captures its achievable rate globally (at any SNR).…”

Improving Performance of Free Space Optics Link Using Array of Receivers in Terrible Weather Conditions of Plain and Hilly Areas

“…The performance of FSO links in the presence of atmospheric turbulence had been analyzed using spatial diversity [10][11]. To calculate the error rate performance, outage probability and diversity gain for multi-input multioutput FSO links, the combined effect of atmospheric turbulence and misalignment was also considered [12][13]. Then the effect of weather conditions was taken into account using array of receivers [14][15][16].…”

Compensating for Optical Beam Scattering and Wandering in FSO Communications

“…In order to improve the FSO link performance; a number of schemes have been proposed including (i) modulation schemes [5,12,13], (ii) channel coding [14]; (ii) automatic beam tracking for building swaying; and (iii) multiple transmitters and receivers for fading effects caused by the atmospheric turbulence [15,16]. Alternatively, a fast steering mirror (FSM) can be used to dynamically direct the light towards the receiver [17].…”