Investigations on Inter-Satellite Optical Wireless Communication

Abstract

The lightwave communication systems are capable of transmitting the signals at very high speeds. Distances up to thousands of kilometers are covered using LASERS and LED‟s as light sources. Inter-satellite link (ISL) has great significance for the global coverage with high rate switching and processing abilities. This concept extents lightwave communication technology into the space technology and the Inter-satellite Optical Wireless Communication. Inter-satellite optical wireless communication link exploits the intermixed features of two most powerful communication technologies Wireless and Optics to transmit data between two points using lasers. This technology is useful where fiber optic cable is impractical. Investigations have been carried out of the system for different linearly polarized modes such as LP00, LP01 and LP02 with return-to-zero (RZ), non-return-to-zero (NRZ) and compressed-spectrum-return-to-zero (CSRZ) modulation formats at varied data rates in terms of Q-factor and eye diagram. A comparison of the three modulation formats is formulated. As the performance of IsOWC is extremely affected by system data rate because Q-factor decreases with increase in the data rate. So results are taken at varied data rates of 5-50 Gbps. The projected setup is simulated for three diverse modulation formats RZ, NRZ and CSRZ using LPnm modes with input power of 0 dBm and transmission distance of 1000 km at operating wavelength of 1550 nm. It has been observed that for any LPnm mode Q-factor increases with increase in Tx/Rx aperture diameter. Results demonstrate successful transmission of LP modes through IsOWC link.