基于FPGA的超高灵敏度收发机研究及实验验证OA

[Objective]The objective of this paper is to address the problem of extremely high link loss in traditional ultra-long unrepeatered communication systems with limited receiver sensitivity of traditional transceiver architectures.An ultra-high sensi-tivity Field Programmable Logic Gate Array(FPGA)-based transceiver scheme is proposed,and a real-time communication scheme for the unrepeatered communication system is proposed by optimizing the traditional coherent Digital Signal Processing(DSP)algorithm.[Methods]The receiver sensitivity of Polarization-Division-Multiplexing Quadrature-Phase-Shift-Keying(PDM-QPSK)signal at different transmission rates is analyzed in simulation,and an ultra-long unrepeatered communication sys-tem of 832.88 km is constructed to experimentally validate the real-time transmission using four Remote Gain Units(RGU).[Results]The simulation analysis shows that the ultra-high sensitivity receiver after optimization has a receiver sensitivity of-53.5 dBm at 2.5 Gbit/s and-59.3 dBm at 625 Mbit/s.The experimental verification of real-time unrepeatered transmission is successfully completed for the PDM-QPSK signal transmission over a distance of 832.88 km and a rate of 625 Mbit/s,where G.654 E fiber and RGUs are used in the transmission link.The total transmission loss of the G.654 E single-mode fibre is 121.2 dB.[Conclusion]The proposed FPGA-based coherent transceiver architecture is capable of achieving high sensitivity signal de-tection at ultra-low received optical power.The transmission distance of the ultra-long unrepeatered transmission system can be further extended by combining it with Raman pump amplifiers and RGUs.