Bidirectional fiber-IVLLC and fiber-wireless convergence system with two orthogonally polarized optical sidebands

Abstract

A bidirectional fiber-invisible laser light communication (IVLLC) and fiber-wireless convergence system with two orthogonally polarized optical sidebands for hybrid cable television (CATV)/millimeter-wave (MMW)/baseband (BB) signal transmission is proposed and experimentally demonstrated. Two optical sidebands generated by a 60-GHz MMW signal are orthogonally polarized and separated into different polarizations. These orthogonally polarized optical sidebands are delivered over a 40-km single-mode fiber (SMF) transport to effectually reduce the fiber dispersion induced by a 40-km SMF transmission and the distortion caused by the parallel polarized optical sidebands. To the best of our knowledge, this work is the first to adopt two orthogonally polarized optical sidebands in a bidirectional fiber-IVLLC and fiber-wireless convergence system to reduce fiber dispersion and distortion effectually. Good carrier-to-noise ratio, composite second order, composite triple beat, and bit error rate (BER) are achieved for downlink transmission at a 40-km SMF operation and a 100-m free-space optical (FSO) link/3-m RF wireless transmission. For up-link transmission, good BER performance is acquired over a 40-km SMF transport and a 100-m FSO link. The approach presented in this work signifies the advancements in the convergence of SMF-based backbone and optical/RF wireless-based feeder.

A Hybrid Internet/CATV/5G Fiber-FSO Integrated System With a Triple-Wavelength Polarization Multiplexing Scenario

“…These CSO/CTB degradations are attributed to the atmospheric attenuation due to 200 m free-space transmission and coupling loss between doublet lens 2 and fiber's ferrule. As the freespace transmission distance is 200 m, with optical CATV modulation, it is to be observed that the CSO/CTB values (≥49.6/50 dB) do not satisfy the end-user CSO/CTB requirements (≥53/53 dB) [30]. With optical VSB-CATV modulation, nevertheless, the CSO/CTB values (≥53/53.4 dB) do meet the end-user demands.…”

“…Furthermore, a digital storage oscilloscope is employed to take the eye diagrams of the delivered 60 Gb/s VSB PAM4 signal. For CATV signal, the filtered 50-550 MHz VSB-CATV even-channel signal (polarized wavelength rotated at a 45 • angle to the x-axis) is received by a CATV receiver, sent to a push-pull scheme to suppress nonlinear distortions [30], and supplied in a spectrum analyzer to measure the CSO and CTB values. As for 16-QAM-OFDM signal, the filtered 70 Gb/s VSB 16-QAM-OFDM signal (x-polarized wavelength) is gotten by a PD, promoted by a low noise amplifier, analyzed by an OFDM analyzer, and post-processed using MATLAB program to evaluate the BER value and the corresponding constellation map.…”

A Bidirectional FSO Communication Employing Phase Modulation Scheme and Remotely Injection-Locked DFB LD

“…An injection-locked DFB LD's bandwidth is several times that of an RSOA. This allows FSO communication enhancing the upstream transmission capacity without using an electrical equalizer [26], [27]. In addition, the upstream performance for employing an injection-locked DFB LD is better than that for employing an RSOA, due to the reduction of laser chirp caused by direct modulation [28].…”

A PDM-based bi-directional fibre-FSO integration with two RSOAs scheme

“…Moreover, establishing a bidirectional fibre-wireless and fibre-FSO integrated system with polarization-orthogonal modulation scheme was shown feasibly 26 . Furthermore, a bidirectional fibre-FSO and fibre-wireless convergence system with two orthogonally polarized optical sidebands had been illustrated 7 . However, the downstream data rate/FSO link of 20 Gbps/100 m 6 , 30 Gbps/10 m 22 , 30 Gbps/50 m 26 , and 20 Gbps/100 m 7 are significantly less than the corresponding values of 128-Gb/s/200-m adopted in this proposed PDM-based bi-directional fibre-FSO integration.…”