Polarization Division Multiplexing-Based Hybrid Microwave Photonic Links for Simultaneous mmW and Sub-6 GHz Wireless Transmissions

Dong-Nhat Nguyen,Zabih Ghassemlooy,Stanislav Zvanovec,Pham Tien Dat,Jan Spacil,Jan Bohata,Matej Komanec,Nobby Stevens

doi:10.1109/jphot.2020.3036440

Abstract

A new hybrid microwave photonic link based on a polarization division multiplexing Mach-Zehnder modulator (PDM-MZM) is proposed. The link enables co-transmission of millimeter-wave (mmW) and sub-6 GHz wireless signals over a seamless single-mode fiber (SMF) and free-space optics (FSO) channels. Optimization of the chromatic dispersion (CD)-induced power fading regardless of the power fading due to the non-deterministic atmospheric turbulence (AT) is simultaneously demonstrated. Extensive simulation analysis is first presented to examine (i) the impact of CD on mmW (25 GHz) and sub-6 GHz (2.6 GHz) signals, envisioned for the 5th generation networks, and (ii) optimization of CD-induced power fading by changing the phase relations between the optical carrier and optical sidebands in each polarization channel using single tunable polarization controller. A proof-of-concept experiment is finally performed to simultaneously deliver 25 GHz and 2.6 GHz signals with 4/16/64-quadrature amplitude modulation over (i) 20 km SMF and 2 m radio wireless link and (ii) 20 km SMF, 4.2 m FSO (with AT) and 2 m radio wireless links. The optimization of the CD-induced power fading is experimentally verified and link performance shows high tolerance to CD with no power penalties and the measured error vector magnitudes well below the required limits. The predicted bit error rates are also below the forward error correction threshold of $2 \times {10^{ - 4}}$.

Highlights

The data traffic on wireless communications is growing exponentially due to the use of everincreasing number of devices, e.g., smartphones, laptops, tablets, etc., requiring access to multiGb/s bandwidth-demanding applications and services
For the first time, to the best of our knowledge, we propose and experimentally demonstrate the co-transmission of mmW (i.e., 25 GHz) and sub-6 GHz (i.e., 2.6 GHz) signals based on the polarization division multiplexing-MZM (PDM-MZM) technique over two configurations of optical distribution network (ODN), which consists of (i) only a single-mode fiber (SMF) channel, namely PDM-MPL and (ii) a hybrid optical link known as PDM-hybrid microwave photonic link (PDM-HMPL) under atmospheric turbulence (AT)
The resultant radio frequency (RF) power reduction between OB2B and PDM-MPL is attributed to the loss of the 20 km SMF since the EDFA is not used in this case

Summary

Introduction

The data traffic on wireless communications is growing exponentially due to the use of everincreasing number of devices, e.g., smartphones, laptops, tablets, etc., requiring access to multiGb/s bandwidth-demanding applications and services. The sub-6 GHz radio access technology (RAT) has been developed for the 5th generation (5G) wireless networks to address this demand [1], [2]. These sub-6 GHz bands offer promising attributes for mobile broadband and possess interesting propagation characteristics to support wide area coverage. To support the growing demand for the bandwidth, the communication industry is moving to the higher radio frequency (RF) range in the millimeter-wave (mmW) bands, e.g., mmW RAT [3]. In early 2020, Global System for Mobile Communications Association updated the 5G spectrum public policy position with the emphasizes on 26, 28 and 40 GHz frequencies, which has currently received the most international support and strong momentum from operators due to the widest harmonization with minimized user equipment complexity [2]

Methods

Results

Conclusion