A full‐duplex dual‐polarization QPSK in a digital radio‐over‐fiber system

Abstract

The author numerically investigates the performance of a 100 Gb/s dual‐polarization quadrature phase‐shift keying (DP‐QPSK) coherent radio‐over‐fiber (RoF) system through deploying various lengths of standard single‐mode fiber (SSMF). The utilization of a microwave photonic integrated circuit (MPIC) as the core building block of this optical coherent RoF link both in downlink and uplink, combined with digital signal processing (DSP) has led to a new RoF scheme which demonstrated the feasibility to operate at the low input RF power. The performance of the RoF system with respect to the optical received power induced by channel SNR is also investigated. It has been demonstrated that for a 200 km length of fiber, a laser with a linewidth of less than 1 MHz results in the EVM compliant to the IEEE standards. It has been also verified that the link offers higher linearity and better receiver sensitivity compared to the conventional intensity modulated and directly detected optical communication systems.

Analysis and Compensation of Chromatic Dispersion in Long-hauls Optical Coherent System

“…The Electronic Dispersion Compensation is implemented using a Frequency Domain Equalizer. Whereas; 5 taps Constant-Modulus Algorithm (CMA) equalizer is realized as a solution for polarization De-multiplexing [21]. As the final step, the carrier phase estimation is performed using a Viterbi-Viterbi algorithm [22] followed by a decision and BER evaluation.…”