Related Experiment Video
Updated: Jun 18, 2026

Transmission of Multiple Signals through an Optical Fiber Using Wavefront Shaping
Published on: March 20, 2017
Generation of optical OFDM signals using 21.4 GS/s real time digital signal processing
Yannis Benlachtar1, Philip M Watts, Rachid Bouziane
1Optical Networks Group, Department of Electronic and Electrical Engineering, University College London, Torrington Place. London. UK. WC1E 7JE. y.benlachtar@ee.ucl.ac.uk
Abstract:
We demonstrate a field programmable gate array (FPGA) based optical orthogonal frequency division multiplexing (OFDM) transmitter implementing real time digital signal processing at a sample rate of 21.4 GS/s. The QPSK-OFDM signal is generated using an 8 bit, 128 point inverse fast Fourier transform (IFFT) core, performing one transform per clock cycle at a clock speed of 167.2 MHz and can be deployed with either a direct-detection or a coherent receiver. The hardware design and the main digital signal processing functions are described, and we show that the main performance limitation is due to the low (4-bit) resolution of the digital-to-analog converter (DAC) and the 8-bit resolution of the IFFT core used. We analyze the back-to-back performance of the transmitter generating an 8.36 Gb/s optical single sideband (SSB) OFDM signal using digital up-conversion, suitable for direct-detection. Additionally, we use the device to transmit 8.36 Gb/s SSB OFDM signals over 200 km of uncompensated standard single mode fiber achieving an overall BER<10(-3).
Related Concept Videos
Reconstruction of Signal using Interpolation
Aliasing
If the sampling frequency is below the Nyquist rate, these replicas overlap, preventing the original signal...
Upsampling
Basic Discrete Time Signals
The unit impulse or sample sequence is mathematically expressed as zero for all n values except at n=0, where it is one. The unit impulse sequence, denoted by δ(n), is the first difference of the unit step sequence, while the unit step sequence u(n) is the...
Generating Electromagnetic Radiations
Discrete-time Fourier transform
One of the notable...
