MIMO Techniques for High Data Rate Free Space
Optical Communication System in Log-Normal
Channel

Mohamed R. Abaza, Raed Mesleh, Ali Mansour†, and Ayman Alfalou‡
Sensor Networks and Cellular System (SNCS) Research Center, University of Tabuk, 71491 Tabuk, Saudi Arabia
{mohamed.raouf.abaza, raed.mesleh}@ieee.org

†Lab STICC, ENSTA Bretagne, 2 Rue Franc¸ois Verny, 29806 Brest Cedex , France, Email: mansour@ieee.org
‡ Laboratory L@BISEN, ISEN-Brest, CS 42807, 29228 Brest Cedex 2, France, Email: ayman.al-falou@isen.fr

Abstract—Multiple input multiple output (MIMO) technique
with equal gain combining (EGC) is considered in this work to
enhance the data rate of free-space optical communication (FSO)
system in log-normal channel. In FSO system, light propagating
in free space is used to transmit data for communication system.
256-ary pulse position modulation (PPM) using intensity modu-
lation with direct detection (IM/DD) as a power efficient system
is employed using PIN receiver. Obtained results demonstrate
that significant boost of data rate can be achieved using MIMO
techniques. Data rate enhances from 350 Mbps to 800 Mbps when
using 2×2 MIMO configuration. As well, 1 Gbps is reported for
4 × 4 MIMO system. These enhancements are achieved without
any bandwidth or power expansions and the bit error rate (BER)
at the receiver is maintained below 10-3.


Index Terms—Free-space optical communications (FSO), M-
ary pulse position modulation (M-ary PPM), Multiple input
multiple output (MIMO), Log-normal channel, PIN receiver.