1,720,972 research outputs found
100 Gbps PON L-band downstream transmission using IQ-MZM CD digital pre-compensation and DD ONU receiver
Full text linkWe propose a downstream direct-detection 100G-PON solution aided by chromatic dispersion digital pre-compensation using an IQ-MZM, allowing L-band operation and 29 dB power budget with low ONU complexity and without requiring single-sideband modulation
Experimental study on 25 Gbps C-band PON over up to 25 km SMF using a 10G-class DML + APD IM-DD system
Full text linkIn this paper we present an experimental analysis of several modulation formats (pulse amplitude modulation (PAM-2), quaternary pulse amplitude modulation (PAM-4) and electrical duobinary (EDB)) for passive optical network (PON) applications at 25 Gbps bit rate in a C-band 10G-class directly modulated lasers (DML) and avalanche photodiode (APD) intensity modulation and direct detection (IM-DD) system over a single mode fiber (SMF) of up to 25 km, optimizing DML operations and demonstrating that PAM-2 is a promising choice. We also theoretically and experimentally analyzed the channel frequency response of DML and SMF affected by DML chirp and SMF chromatic dispersion
100+ Gbps/λ 50 km C-Band Downstream PON Using CD Digital Pre-Compensation and Direct-Detection ONU Receiver
Full text linkWe experimentally demonstrate a single-wavelength 100 Gbps downstream PON transmission aided by chromatic dispersion digital pre-compensation (CD-DPC) using simple digital signal processing (DSP) finite impulse response (FIR) filters in combination with an IQ Mach-Zehnder modulator (IQ-MZM) at the transmitter side and direct-detection receiver at the optical network unit (ONU). A reach of 50 km over standard single-mode fiber in C-band and an optical distribution network (ODN) loss of 28.5 dB are achieved. Transmission of 50 and 125 Gbps over 50 km of fiber is also tested, achieving 32 dB and 24 dB of ODN loss, respectively. The complexity of the filters, the optimization of the main design parameters, and the tolerance of the CD-DPC to the uncertainty of the exact accumulated link dispersion are analyzed in detail
100 Gbps/λ PON downstream O- And C-band alternatives using direct-detection and linear-impairment equalization [Invited]
Full text linkThe future-generation passive optical network (PON) physical layer, targeting 100 Gbps/wavelength, will have to deal with severe optoelectronics bandwidth and chromatic dispersion limitations. In this paper, largely extending our Optical Fiber Communication Conference (OFC) 2020 invited paper, we review 100 Gbps/wavelength PON downstream alternatives over standard single-mode fiber in the O- and C-bands, analyzing three modulation formats (PAM-4, partial-response PAM-4, and PAM-8), two types of direct-detection receivers (APD- and SOA + PIN-based), and three digital reception strategies (unequalized, feed-forward equalized, and decision-feedback equalized). We evaluate by means of simulations the performance of these alternatives under different optoelectronics bandwidth and dispersion scenarios, identifying O-band feasible solutions able to reach 20 km of fiber and an optical path loss of at least 29 dB over a wide wavelength range of operation. Finally, we compare two digitally precompensated modulation schemes that are highly tolerant of chromatic dispersion, showing a possible extension to C-band operation, preserving direct-detection and linear-impairment equalization at the optical network unit side
Experimental Demonstration of DSP-Assisted Electrical Duobinary Optimization for High Speed PON 25+ Gbps Using 10 Gbps APD Receiver
No full textWe compare experimentally two variants of electrical duobinary using adaptive equalization for 25-40Gbps high-speed PON, showing the advantageous of designing an automatic digital signal processing receiver selecting the more appropriate adaptive equalization depending on available bandwidth and link dispersio
Alternative solutions for fronthauling based on DSP-assisted Radio-over-Fiber
No full textWe review alternative solutions for optical fronthauling in next generation fixed-mobile converged architectures that try to solve the problems related to the extremely high bit rates required by current fronthauling implementations based on the so-called digitized Radio over Fiber (as for the CPRI or OBSAI standards). In particular, we present our most recent results on Digital Signal Processing (DSP) assisted Frequency Division Multiplexed (FDM) aggregated radio over fiber solutions. We experimentally show two DSP-based optimization at the transmitter and/or receiver that improves the received Error Vector Magnitude (EVM). Moreover, we discuss on simple spectral estimation of the EVM parameter at the Remote Radio Head (RRH)
200 Gbps/λ PON Downstream C-Band Direct-Detection Links with ≥29 dB Power Budget
Full text linkIn this paper we present the simulative analysis of a 200 Gbps per wavelength (λ) 8-level pulse amplitude modulation (PAM-8) downstream communication over up to 20 km single mode fiber (SMF) in C-band based on direct detection (DD) achieving at least a 29 dB link power budget in a PON environment. We use chromatic dispersion digital pre-compensation (CD-DPC) and a dual-arm in-phase and quadrature Mach–Zehnder modulator (IQ-MZM) at the optical line termination (OLT) side, while preserving DD in the optical network unit (ONU). Three receiver digital-signal-processing (DSP) options are analyzed and compared: square-root-like technique (SQRT) in combination with a feed forward equalizer (FFE) and a decision feedback equalizer (DFE), the Volterra nonlinear equalizer (VNLE), and the SQRT in combination with the VNLE. The SQRT can be applied in combination with the VNLE to decrease the receiver DSP complexity while maintaining the required system performance. We show that PAM-8 with CD-DPC and the SQRT in combination with the VNLE is a feasible solution for 200 Gbps per λ downstream C-band transmission for PON
100 Gbps/λ C-Band CD Digital Pre-Compensated and Direct-Detection Links with Simple Non-Linear Compensation
Full text linkIn the scenario of downstream Passive Optical Networks (PON), we analyze through simulations and experiments a 100 Gbps/λ link using digital signal processing (DSP) over up to 50 km single mode fiber (SMF) in C-band. In particular, we propose chromatic dispersion digital pre-compensation (CD-DPC) and quaternary pulse amplitude modulation (PAM-4) levels optimization at the transmitter side (TX), and simple non-linear compensation (NLC) in combination with adaptive equalization (AEQ) at the receiver side (RX). Regarding NLC, we compare two approaches: a quadratic polynomial function and a square-root-like function respectively. In this paper, we analyze in detail the performances of four proposed options, namely equispaced PAM-4 levels without NLC (baseline case), equispaced PAM-4 levels in combination with NLC, optimized PAM-4 levels without NLC, and optimized PAM-4 levels in combination with NLC. We demonstrate through simulations and experiments that optimized PAM-4 levels can only offer limited enhancement when NLC is applied, and up to 3.3 dB sensitivity gain can be obtained thanks to NLC at RX when setting the optimum parameters, with respect to the baseline case
Overview of high-speed TDM-PON beyond 50 Gbps per wavelength using digital signal processing [Invited Tutorial]
Full text linkThe recent evolution of passive optical network standards and related research activities for physical layer solutions that achieve bit rates well above 10 Gbps per wavelength (lambda) is discussed. We show that the advancement toward 50, 100, and 200 Gbps/lambda will certainly require a strong introduction of advanced digital signal processing (DSP) technologies for linear, and maybe nonlinear, equalization and for forward error correction. We start by reviewing in detail the current standardization activities in the International Telecommunication Union and the Institute of Electrical and Electronics Engineers, and then we present a comparison of the DSP approaches for traditional direct detection solutions and for future coherent detection approaches. (c) 2022 Optica Publishing Grou
Direct-detection 25 Gb/s PON: PROs and CONs of digital signal processing at the transmitter side
Full text linkWe evaluate the performance of direct-detection 25 Gb/s Passive Optical Networks (PON) with adaptive equalization at the receiver side, comparing three transmitter schemes: two including digital signal processing (DSP), namely square-root raised-cosine pulse shaping and pre-emphasis, and the third one without any DSP pre-compensation. We show that DSP at transmitter side can provide a performance advantage only under strong bandwidth limitations and when considering feed-forward equalization (FFE) at the receiver. When including decision-feedback equalization (DFE), the use of pre-compensation at transmitter does not provide any advantage under linear transmission
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