With the technological shift towards big data, internet of things (IoT), 5G applications and cloud
computing, the demand for high capacity networks is dramatically increasing. To avoid congestion
and saturation, content and service providers are re-designing their network (backbone, metro
and data-centers interconnects) connectivity using gridless optical line systems along with
programmable coherent transponders. The latter are expected to transmit data at different data
rates up to 400 Gb/s. In 2008, the first coherent receiver was commercially available [1]. By means
of high-speed analog to digital converters and adaptive digital signal processing (DSP) algorithms,
such revolution in modern optical communication was possible. That allowed a better spectral
efficiency using higher order modulation formats and further signal reach by means of
compensating both linear and nonlinear impairments. Another key development was leveraging
light polarization-diversity, that permits to double the data rate at the expense of receiver
complexity. To further increase the capacity of fiber links, gridless DWDM networks are being
developed for deployment in the next few years. The key idea is to allow variable bandwidth
signals to be allocated on optical links and by performing the appropriate network layer
optimization improved throughput can be achieved. These innovations are driving new types of
challenges for routing and assignment methods, as well, DSP algorithms such as clock recovery
and compensation of fiber non-linearity.
This thesis is organized as a collection of contributions and composed of five major parts. The
first part, consisting of chapters 2 and 3. Chapter 4 deals with tracking of fast state of polarization
transient, i.e. dynamic aspect of optical channels, in presence of polarization dependent loss
(PDL) and filtering effects due to reconfigurable optical add-drop multiplexers (ROADMs).
Chapters 5 and 6 study the impact of filtering effects, quasi-static effects in optical links and
transponders, represented by ROADMs in fixed-grid and Silicon Photonics (SiPh) modulators in
flexible-grid networks, respectively. Chapters 7, 8 and 9, are related to clock recovery in digital
coherent receivers. They cover mitigation of jitter in gridless applications, improving jitter when
deploying phase interpolators (PI) and jitter injection as a test-mean to evaluate performance.
| Identifer | oai:union.ndltd.org:uottawa.ca/oai:ruor.uottawa.ca:10393/38507 |
| Date | 30 November 2018 |
| Creators | Abdo, Ahmad |
| Contributors | D'Amours, Claude Denis |
| Publisher | Université d'Ottawa / University of Ottawa |
| Source Sets | Université d’Ottawa |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Format | application/pdf |
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