Comparison Between Kramers-Kronig and Self-coherent Transceivers for Free Space Optical Communications

Both Kramers-Kronig and self-coherent transceivers use a pilot carrier at the transmitter and as a result, the oscillator-signal mixing efficiency is much higher than coherent transceivers. However, Kramers-Kronig transceivers suffer from poor transmitter power efficiency while self-coherent transceivers require a larger receiver bandwidth due to heterodyne detection. The performance of Kramers-Kronig transceivers is better than self-coherent transceivers, provided that the pilot carrier power is sufficiently large.