EPIC-DSP: Enabling Power Efficient Optical Communication through Novel Digital Signal Processing
Funder: Royal Academy of Engineering
Lead partner: UCL
Partners: British Telecommunications PLC; KDDI Research, Inc.; National Institute of Information and Communications Technology; OFS Fitel, LLC; University of Bath
Lead academic: Dr Eric Sillekens
Project amount: £781,250
Research themes: Semiconductors; Control & Signal Processing
Project period: 1 August 2024 - 31 July 2029
Project description: The digital communication infrastructure, underpinning the internet, represents 3% of global power usage and internet traffic is growing by 10% every year Optical communication systems contribute 30% to this due to the numerous optical fibre amplifiers used to compensate for signal loss (with 99% of input power being lost over 100 km). This fellowship would transform these systems by introducing low-complexity digital signal processing (DSP),allowing novel system architectures with the aim of lowering energy consumption. The first system being investigated in the fellowship would aim to reduce energy consumption by30-50% through the use of low-power semiconductor optical amplifiers (SOAs) and hollow core optical fibres (HCF). Optical fibre amplifiers work by using electrical power to drive a pump laser, itself used to provide signal gain. However, in semiconductor optical amplifiers, the gain is generated directly from the electrical signal, saving a conversion step and, with it, power. However, crosstalk due to the nonlinear gain dynamics within the SOAs affects the signal quality and is currently preventing their adoption; novel DSP, based on machine learning and implemented within the optical receivers, developed within this Fellowship, will overcome these distortions. Moreover, introducing lower-loss HCF decreases the amplifier count, whilst simultaneously simplifying the DSP because of the fibre’s significantly reduced dispersion and nonlinearity. The increased energy efficiency arises from two contributions: firstly, energy is saved by using a more energy efficient amplifier; secondly, the lower pulse spreading in HCF, compared to standard fibre, has the effect of significantly reducing the number of samples which the DSP needs to simultaneously process to recover each symbol, and this results in lower energy consumption.
To date, SOAs and HCF have been investigated separately (HCF at Lumenisity and SOAs for transmission at Huawei and Nokia). However, this Fellowship research aims, for the first time, to combine their use and exploit the symbiosis between SOAs and HCF, increasing the effectiveness of the DSP, and overcoming the disadvantages blocking widespread adoption of these technologies .Besides transforming energy efficiency and data throughput of optical systems, this Fellowship would allow me to establish partnerships and position myself as an independent researcher in the emergent field of DSP for energy-efficient communication.
