Method for atmospheric optical free space transfer of digital signals and recipients for the method

摘要

The method involves modulating a laser beam by a differential phase shift keying modulation allowing direct detection modulation with an incoherent reception. An incoherent direct detection is carried out in a demodulator (7) on the receiving-side. Another detection is carried out additionally on the receiving-side in a coherent demodulator (6) that is operated with a laser local oscillator (LO). The two electrical signals detected by both the demodulators are subjected to a diversity-forming signal optimizing selection or combination process. An independent claim is included for a receiver for atmospheric optical free space transfer of digital signals.