Optical Intersatellite System Based on DPSK Modulation

The use of optical carrier for intersatellite link (ISLs) can lead the whole system at higher data rates performing low probability of jamming, lower interference, lower power requirements and smaller antenna size. The choice of 1550 nm wavelength technology gives rise to some problems, such as higher antenna size, but offers important benefits: less Doppler shift, less complexity in tracking and acquisition procedure. The main constraint affecting the system performance concerns on the Doppler effect suffered by the signal due to the relative movement between satellites. An analysis of the optical transmitter/receiver performance, operating at 1550 nm will be developed. The communication system is based on a DPSK modulator with direct detection receiver, in order to improve system sensitivity with respect to conventional intensity modulation-direct detection (IM-DD) systems