Date – 26th June, 2019
Time – 11:00 AM
Venue – ESB 244
Speaker – Lakshmi Narayanan V (EE14D402)
Advisor(s) – Prof. Deepa Venkitesh & Prof. David Koilpillai
With ever increasing network traffic with an exponential growth rate of up to 60% per year, the next generation fiber-optic networks focus on the spectrally efficient ways of providing high capacity transport infrastructure for both long-haul (>100 km) and short-haul systems (<100 km).
In the first seminar talk, we presented the basics of coherent optical modem and the specific digital processing algorithms for channel equalization and compensation of the typical impairments for QPSK and 16-QAM modulations. We also presented the details of experimental results for transmission of 128 Gbps & 256 Gbps using single optical carrier and of 400 Gbps & 512 Gbps using optical super-channels.
In this seminar, the first part will focus on the introduction of Coherent Optical Orthogonal Frequency Division Multiplexing (CO-OFDM) along with associated optical impairments and its equalization. The later part of the seminar will focus on the effect of oscillator phase noise – which is the most critical impairment in CO-OFDM systems. We propose a new algorithm based on Kalman filters to mitigate the common phase error and compare its performance, both numerically and experimentally, against the standard pilot aided algorithm. The performance evaluation is carried out by evaluating the bit error rate (BER) and/or error vector magnitude (EVM) for different signal-to-noise ratios.
All are cordially invited.