Yanir London

Nonlinear Effects Mitigation in Coherent Optical OFDM System in Presence of High Peak Power

The nonlinear effects of Mach-Zehnder modulator (MZM) and self phase modulation (SPM), in optical orthogonal frequency division multiplexing (OFDM) under the presence of high peak power is studied. A full coherent optical communication system is presented and analyzed. Standard method to reduce the peak to average power ratio (PAPR) values combined with improved technique to mitigate the nonlinear effect, by means of optimized digital pre-distortion, is analyzed and a full performance analysis is presented.

Analysis of nonlinearity of Mach-Zehnder modulator in coherent optical OFDM in the presence of PAPR

The nonlinearity of Mach-Zehnder modulator, in present of high peak power of optical orthogonal frequency division multiplexing (OFDM) is studied. A full optical coherent communication system is presented and analyzed numerically. A study of the effect of peak to average power (PAPR) reduction technique on the performance of the offered Optical-OFDM is shown.

Spectrally Fragmented Electrical Dispersion Compensation for High-Speed Microstrip Traces in Data Centers Connections

The frequency-dependent dispersion impairment of high-speed printed analog traces in next-generation pluggable modules is studied. This frequency dependence is considered for the first time in optical fiber communication systems. Transmission of ultra-broadband electrical signals over such traces dramatically enhances the frequency-dependent dispersion effect. Here, for the first time, an extended model of the ultrabroadband signal transmission that includes this frequency-dependent dispersion effect of the printed analog traces is proposed. Additionally, a novel approach to compensate for this frequency-dependent dispersion impairment is introduced. Inclusive analysis reveals that a significant performance improvement of up to 4 dB is achieved by using the proposed symbol-spaced sampling and reduced-complexity digital signal processing technique.

Enhanced Fractional Electrical Dispersion Compensation for High-Speed Analog Traces in Data Center Intra-Connections

We propose a new fractional-EDC technique for high-speed analog dispersive transmission lines that are integrated in data center backplanes. Compared to classical-EDC, the proposed EDC improves the SNR performance up to 2dB.

Inclusive Modeling and Digital Compensation for Coupling Impairments of High-Speed Coupled Electrical Microstrip Traces in 100G OOK and PAM4 Data Center Connections

Pluggable transceiver modules become the preferable form factor in data centers connectivity due to the lower power consumption and smaller size, which allows high port density. In such small form factors, the optical components may be packaged separately from the electronic blocks. This introduces a new challenge for transmission of ultra-broadband signal over high-speed coupled printed analog traces, as the coupling impairments are enhanced dramatically. Here, an extended model of coupling impairments of coupled microstrip traces in optical fiber communication systems is proposed. This model consists of an accurate formulation of the frequency dependency, which is shown to be critical in the transmission of ultra-broadband signals. In addition, a comparison is presented to standard practice coupling models that are currently being used for crosstalk cancellation techniques in sub-10G systems or very short traces. Based on the inclusive coupling model, novel coupling compensation techniques are proposed and are compared with the classical ones. Comprehensive analysis, which is verified by Monte-Carlo simulation, reveals that the newly introduces coupling compensation technique significantly outperforms the existing crosstalk compensation solutions, for 25G transmission and beyond, thus, longer coupled traces are supported. The new approach is based on symbol-spaced sampling and reduced-complexity digital signal processing. It is shown in the case of 100G PAM4 transmission, based on commercially available 25G components, the newly proposed compensation technique supports long microstrip traces of more than 15 cm, while maintaining 10-3 pre-forward error correction (pre-FEC) bit error rate (BER).

Advanced modulation formats and digital signal processing for next generation fiber optics networks

Advanced modulation formats are proposed and analysed for next generation optical networks. The new evolving optical networks data rates of 100G and above require real time analog-to-digital conversion followed by real time digital signal processing. This is in order to allow increased spectral efficiency and full compensation of amplitude and phase distortion imposed by the optical channel in such high bitrates. Various approaches are presented, including discrete multi-tone and optical OFDM.

Analysis and mitigation of Mach-Zehnder modulator nonlinearity in coherent optical OFDM system in the presence of high peak power

The nonlinear effect of Mach-Zehnder modulator (MZM) in optical fiber under the presence high peak power of optical orthogonal frequency division multiplexing (OFDM) is investigated. A full optical coherent communication system is presented and analyzed numerically. A method to mitigate the nonlinear effect by means of digital pre-distortion is proposed. Inclusive quantitative analysis of the effect of peak to average power (PAPR) reduction on the performance of the proposed Optical-OFDM system is presented.