"Free-space optical (FSO) communication is a license-free access technology with high-bandwidth capacity. It is a powerful alternative and/or complementary solution to commonly deployed fiber optic and wireless radio-frequency links. FSO is appealing for a number of applications including metropolitan area network extensions, enterprise/campus network connectivity, fiber back-up, back-haul for wireless cellular networks, disaster recovery, and quantum key distribution among others. Despite the major advantages of FSO technology and variety of its application areas, its widespread use has been hampered by its rather disappointing performance for long-range links. The major performance limiting factor for FSO links with ranges longer than one kilometer is the atmospheric turbulence-induced fading. Building upon the concept of cooperative diversity, the proposed research will devise efficient physical layer solutions tailored for the inherent characteristics of the FSO channel that remedy the shortcomings of existing systems. The proposed systems and techniques will provide a novel research framework on the design and analysis of relay-assisted (cooperative) FSO transmission. The results of this proposed research will be instrumental in the building of long-range, highly reliable, and ultra-fast FSO systems to meet the demanding requirements of next generation communication networks. This proposal is in fact a natural continuation of the applicant Dr. Uysal’s internationally renowned research program on FSO communication which he has carried out at the University of Waterloo in Canada. The Marie Curie International Reintegration Grant, if funded, will help Dr. Uysal transfer this internationally visible research program to Europe."