Report

Teaser, summary, work performed and final results

Periodic Reporting for period 1 - COIN (Coding for Optical communications In the Nonlinear regime)

Teaser

Data demand, stimulated by prevalence of social media, video and new services keeps growing at 40% per year and the capacity to carry this data is lagging behind. This potentially has dramatic consequences on the economy, rationing demand or raising prices. This research...

Summary

Data demand, stimulated by prevalence of social media, video and new services keeps growing at 40% per year and the capacity to carry this data is lagging behind. This potentially has dramatic consequences on the economy, rationing demand or raising prices. This research project aims to close this gap caused by the nonlinear properties of the optical fibre and develop nonlinear modulation, coding, and detection methods, tailored to the nonlinear channel, to dramatically improve the data throughput of future communication networks.
The COIN objective is, thus, the development of a new area of nonlinear communications including forward error correction, essential for reliable communication. Specifically, COIN will investigate the application of nonlinear Fourier transforms and nonlinearity-tailored coding and detection by effectively integrating the scientific expertise of the key academic research groups in information theory, coding, coherent optical communication and high-speed transmission with the industrial know- how of the consortium.
The COIN R&D goals will be to focus on the development of new, native communication schemes and waveforms alongside with the development of coding schemes for these and existing non-linear Fourier transform based transceivers. The R&D tasks will be carried out along with researcher training in the leading scientific centres in Europe.

Work performed

WP 1 – Uncoded Nonlinear Transmission Schemes
ESR1 focused on the review of approaches native nonlinear transmission schemes for optical fibre communications, focussing his research on the nonlinear Fourier transform (NLFT) and nonlinear frequency division multiplexity (NFDM), which is the nonlinear analogue of wavelength division multiplexing. NLFT, itself, is a method for transforming a signal to a domain where it is unaffected by optical fibre nonlinearity, and can therefore, theoretically, be detected and recovered without distortion. His research initially focussed on single polarisation transmission, for which NLFT algorithms already exist. This work is summarised in D1.2, he was able to compare the achievable information rates (AIR) between WDM and NFDM transmission systems. After starting his secondment at NOKIA,, ESR1 has been actively working on the optimization of a novel nonlinear transmitter architecture which takes the fibre nonlinearity into account in a constructive way.
WP2 – Coding and Coded Modulation Schemes for Nonlinear Transmission
ESR2: The work undertaken by ESR2 began with an investigation into the effects which impact on achievable information rates (AIR). Nonlinearity-induced spectral broadening in optical fibre communications was found to not only heavily impact on the performance of signal propagation, but was directly linked to both nonlinearity mitigation schemes and AIR (and, hence, the FEC schemes required for nonlinear transmission). Using this new understanding of the phenomenon, he was able to extend this work by analysing the impact of span length on AIR, when constraining the transmission system to a bandwidth-optimised, single channel, DBP algorithm. He was able to show that optimising DBP and span length in this way can reduce the FEC requirements, or decrease the number of repeaters required for a long-haul transmission system.
ESR4: The work started with the derivation of the capacity achieving distribution for an NFT-based transmission system where data is embedded into the imaginary part of the nonlinear discrete spectrum. We then proposed a probabilistic shaping scheme based on LDPC codes that shapes the transmitted symbols such that the obtained distribution approximate as closely as possible the desired distribution and derived its achievable rate. We finally showed using simulations that the proposed scheme provides twice the data rate compared to an unshaped system.
WP3 – Transmission Regime and Experimental Verification
Different experimental setups have been proposed and setup as highlighted in Deliverable D3.1. We have in particular built and made available to the ESRs: a fully versatile loop setup that can be used to test any transmission system, a full Nonlinear-Fourier-Transform (NFT) based transmission system to be used for NFT and a short-reach system with square-law detection that his used by neural-network based transceivers.
WP 4 – Project Management & Doctoral Training
In the first period, the COIN project management structure was set up, the four ESRs were recruited and all the deliverables were submitted. Internal communication tools were set up, project meetings were organised to share information and collect feedback from the partners.
WP5 – Exploitation, Dissemination & Outreach
The results of the project have been presented at the university sites in order to discuss the relevance of the proposed topics and to raise awareness on the project and expected outcome, at the industrial partner to raise awareness of the stakeholders, as well as in international conferences and journals. ESRs and PIs have participated in multiple workshops and exchanged ideas and a web-page has been successfully launched.

Final results

Wider societal implications
Greater digital connectivity is inevitable and essential. The question of how to ensure the availability of ubiquitous, high-capacity, low-delay, resilient and secure digital infrastructure, likely to transform and improve people’s lives, forms the subject of our proposal. Every sector of the population and Government/private agencies is likely to be affected:
-General public inc (i) children, (ii) the elderly, (iii) patients and disabled, (iv) rural communities, the possibility of having ubiquitous access to bandwidth with low-delay will enable the transformation of people’s lives at every stage of development: (i) children to access educational services, courses, university laboratories and expert teaching at a push of a broadband button, eliminating time lost due to illness, non-availability of specialist teachers or access to facilities; (ii) the elderly & disabled – to allow real-time monitoring and remote healthcare for housebound individual in need of care and company (iii) patients and disabled – access to leading specialists, tests and even treatment without the need to travel to appointments; (iv) rural communities – to reduce the isolation and improve the connectivity of the entire country will help reduce concentration of population in urban areas and improve national prosperity.
-Government, government agencies, service providers: there are enormous cost-savings to be made from the provision of flexible, secure, high-bandwidth connectivity, as well as potential improvements in productivity through availability of broadband digital services
-Manufacturers/maintenance – advances in communications and infrastructure will also improve productivity and, thus, profitability. Introducing self-driving elements will reduce maintenance costs and improve competitiveness and very importantly – resilience and reliability. Optical networks forming the core of the communications infrastructure also control all other infrastructure – transport (rail, roads, air traffic) and utilities – their reliability and resilience and the inter-operability is key to national wellbeing, security and safety.

Website & more info

More info: http://www.coinproject.eu/.