High bit rate Free Space Optical link based on Pulse Position Modulation and DPSK

Abstract

Optical Wireless Communication (OWC), with its high bandwidth, easy deployment, no license requirements, protection from electromagnetic interference (EMI) and enhanced security, has emerged as a frontrunner for high-speed broadband, surpassing traditional radio frequency (RF) systems. Research presents a novel all-optical technique to transmit multiple channels of data over an optical link using DPSK and pulse position modulation (PPM) schemes. The combination of DPSK and PPM also makes eavesdropping and interception extremely difficult. Simulation results show that the technique achieves error-free transmission of the three channels at a data rate of 30 GHz, demonstrating better security and spectral efficiency than conventional methods. Furthermore, the study extends the application of this technique to inter-satellite links, enhancing link availability for small LEO satellites through integration with a GEO data relay satellite. As the demand for secure and high-speed communication escalates, this technique holds potential for practical deployment and seamless integration into emerging communication networks.