A full duplex FSO transmission system using RZ-4PAM downlink signals with 67% duty cycle and AMI uplink signals

Abstract

To improve the transceiver quality of Free Space Optical (FSO) system and ensure that user access is feasible the network, a high-speed full-duplex 100 meters FSO transmission scheme using 67% duty cycle RZ-4PAM downlink and alternative mark inversion (AMI) uplink signals is designed system. In the downlink, one PAM sequence generator and one Mary pulse generator (MPG) module are used to generate 67% RZ-4PAM optical signals at 10Gbit/s through a Mach-Zehnder intensity modulator (MZM). The upstream AMI signals generator by the pseudo-random binary sequence (PRBS) generator and the precoding process. We have measured optical spectrums, time-domain waveforms and eye diagrams before and after signals transmission by system simulation. The transceiver performance of the downstream RZ-4PAM with 67% duty cycle and upstream AMI optical signals the in the 100m FSO transmission system is analyzed.