Numerical Analysis of a Multi-Function Photonic Integrated Circuit for Coherent Radio-Over-Fiber

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

“…A system has been recently proposed and numerically demonstrated in, where the microwave photonics integrated circuit (MPIC) is used for three roles; (i) spatially‐separated carrier generation for remote heterodyning, (ii) IQ‐modulation in the downlink (iii) up‐conversion in the uplink. It has been shown that the spectral purity of the laser source has a negligible effect on the linewidth of the mm‐wave carrier generated by heterodyne mixing, which is solely determined by the linewidth of the RF driving signal . In the counterpart, the heterodyne mixing of two distinct laser sources results in an RF carrier featuring a linewidth proportional to that of the two optical sources.…”

“…Although the matter may be relevant from the computation time viewpoint, its effect in the present work is negligible because the width of the simulated structure is in the tens of micrometers range and the number of simulated modes in both ideal and nonideal is significantly large. Results illustrate the benefits of using the MPIC as SSB modulator at the downlink due to the fact that the lower and upper sidebands are obtained physically in distinct ports of the circuit, facilitating the modulation of one output without the need of an optical filter. Simulation results also illustrate the use of the MPIC as an IQ modulator of either a baseband or an intermediate frequency (60 GHz) modulated signal.…”

“…The numerical analysis of a back‐to‐back (B2B) digital coherent radio‐over‐fiber (RoF) system comprising a microwave photonic integrated circuit (MPIC) as the main building block was proposed in a recent publication . The MPIC was analyzed in the uplink as a single‐side band (SSB) up‐converter of a 60‐GHz frequency‐shifted input.…”

“…After transmission through a fiber optic span, the optical SSB signal reaches the central office and is detected using an optical coherent receiver . It has been verified that the fiber‐optic link can operate perfectly even with a weak input RF signals as low as −55 dBm for the back‐to‐back system …”

“…This paper completes and further extends the recent work presented in by applying DSP algorithms at the coherent receiver which enables transmission over higher length of standard single‐mode fiber (SSMF) and doubls the capacity via polarization multiplexing. The numerical investigation on the impact of fiber length on the recovery of the data and the benefits of utilizing DSP in comparison to conventional systems are outlined.…”