Bidirectional colorless WDM-PON RoF system with large spurious free dynamic range

Abstract

A bidirectional colorless wavelength-division-multiplexed passive optical network radio over fiber system with a large spurious-free dynamic range (SFDR) is proposed. By separating the unmodulated optical carrier from the polarization multiplexed optical signal in the optical network unit, upstream wavelength reuse is realized. By adjusting the angle and phase difference between the orthogonal optical polarization modes, third-order intermodulation distortion (IMD3) suppression of the downstream link is realized. The periodic power fading caused by dispersion in the system is solved through single sideband modulation. Experiments have verified the wavelength reuse effect of the upstream link. Compared with the traditional link based on a Mach–Zehnder modulator, the periodic power fading of the system is suppressed under different radio frequencies (RFs) and fiber lengths. The IMD3 of the downstream link is suppressed, and the SFDR is improved by more than 17 dB. Also, the proposed system is tested with a 16 quadrature amplitude modulation RF signal in the experiment, where a good adjacent channel power ratio and error vector magnitude of the system are obtained.

A novel multi‐ary PolSK modulation for downstream signal in wavelength reusing wavelength division multiplexing passive optical network

“…proportional to the square of oscillation amplitude, so the four polarizations are converted to two optical amplitudes that are cos 2 22.5°(~0.85) and cos 2 67.5°(~0. 15). The decision level could be set at 0.5 to distinguish A/B from C/D.…”

“…Another way to achieve colorless ONUs is upstream remodulation. [15][16][17][18][19][20][21][22][23][24][25][26][27][28] The downstream signals of different wavelengths are wavelength division demultiplexed by the wavelength division demultiplexer in the remote node. In each ONU, part of the downstream signal is drawn out for upstream remodulation.…”

“…Another way to achieve colorless ONUs is upstream remodulation 15–28 . The downstream signals of different wavelengths are wavelength division demultiplexed by the wavelength division demultiplexer in the remote node.…”

A method for mitigating the phase imbalance and insertion loss in the optical mm- wave system for 5G communication network

“…Several researchers discussed the phase imbalance of the mm-wave such as the bidirectional colorless WDM-PON RoF system, in this (Wang et al, 2022) study, the periodic power fading caused by dispersion has been solved by modifying the angles and phases of the signal. Another study (Zabala-Blanco, Campuzano, Aldaya, Castañón, & Vargas-Rosales, 2018) reported the impact of partial phase imbalance, it discussed that the phase imbalance and phase noise for optical signals cause a chromatic dispersion in ber progressively and then limited the maximum achievable range of the signal.…”

Filterless and Compact ANy-WDM Transmission System Based on Cascaded Ring Modulators

“…However, the modulation of the n WDM channels in the transmitter requires to use WDM filters [15], [16] or arrayed waveguide gratings (AWGs) [17] to select between the wavelengths. Thus, n optical branches are established.…”