FPGA emulation of polarization-mode dispersion in optical fibers

Abstract

Improving the transmission capacity through polarization-division mode (PDM) technology has given rise to polarization-mode dispersion (PMD) effect in opti cal fiber communication system. Research and analysis of how various parameters on optical fiber PMD will impact the system performance can help us reducing or equalizing PMD more efficiently. But the parameters cannot be easily changed in the optical fiber experiment to observe the impact on PMD. Therefore, we have built a real-time digital model of PMD based on field-programmable gate array (FPGA), which can change the parameters during operation and capture the output signal after adding PMD. At the same time, a general equalizer digital model was built to handle the PMD impairment. We build a two-polarization optical fiber emulating system which includes transmitter, additive white Gaussian noise (AWGN), PMD emulator, equalizer and receiver. This system allowed us to observe the impact of changing the various parameters of the PMD on the equalizer.