Receive-diversity-aided power-fading compensation for C-band IM/DD OFDM systems

Abstract

A receive-diversity-aided power-fading compensation (RDA-PFC) scheme is proposed and demonstrated to eliminate the chromatic dispersion (CD)-induced power fading for C-band double-sideband (DSB) intensity modulation and direct detection (IM/DD) orthogonal frequency division multiplexing (OFDM) systems. By combining the responses before and after a dispersive element using a maximal-ratio combining (MRC) algorithm, the CD-induced power fading dips within the signal bandwidth of around 50 GHz can be effectively compensated for, which results in an up to 17.6-dB signal-to-noise ratio (SNR) improvement for the fading subcarriers after transmission over 10 km of standard single-mode fiber (SSMF). Using the 16 quadrature amplitude modulation (QAM) format, a diversity receiver with the proposed RDA-PFC scheme can support 170.6-Gbit/s OFDM signal transmission over a 10-km SSMF and reduces the bit error rate (BER) by more than an order of magnitude compared with a conventional receiver. Moreover, 208.1-Gbit/s adaptive bit and power loading OFDM signal transmission over a 10-km SSMF is realized by the proposed RDA-PFC scheme, which improves the capacity by 15.3% compared with the case without RDA-PFC at a BER of 3.8 × 10−3. The proposed RDA-PFC scheme shows great potential in CD-induced power-fading compensation for high-speed IM/DD OFDM systems.

Parallel Wavelength-Division-Multiplexed Signal Transmission and Dispersion Compensation Enabled by Soliton Microcombs and Microrings

“…The ultra-low-loss waveguide was fabricated on an 800-nm-thick Si3N4 layer, deposited by low-pressure chemical vapor deposition (LPCVD) by Ligentec. The device was patterned using 193-nm photolithography and the quality (Q) factor of the microring resonator is 7×10 5 to support the generation of the soliton microcomb. The Si3N4 chip was packaged with a pair of fiber arrays and the coupling loss is ∼3 dB/facet after being fixed by an ultra-violet (UV) curable adhesive.…”

“…As a result, there is a critical need for energy-efficient and cost-effective DCIs that can accommodate a substantial capacity. For short-reach DCIs spanning distances of less than 40 km, the utilization of intensity modulation and direct detection (IM-DD) has emerged as a practical and preferred solution [3][4][5] . This choice is motivated by the inherent advantages IM-DD offers, including cost-effectiveness, a low power consumption, and a compact physical footprint.…”

Gluon contribution to the mechanical properties of a dressed quark in light-front Hamiltonian QCD

“…The gluon GPDs and form factors have been calculated in a soft-wall ADS/QCD model in [48]. In a very recent paper [49], gluon GPDs have been calculated in a light-front spectator model, where the proton state is assumed to be consisting of one gluon and one spectator particle containing three valence quarks. The gluon GPDs and GFFs for nucleon have been investigated in a holographic QCD framework in the context of photoproduction or leptoproduction of J/Ψ and Υ in [50].…”