Generation of optical OFDM signals using 21.4 GS/s real time digital signal processing.
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).
Benlachtar
Yannis
Y
Optical Networks Group, Department of Electronic and Electrical Engineering, University College London, Torrington Place. London. UK. WC1E 7JE. y.benlachtar@ee.ucl.ac.uk
Watts
Philip M
PM
Bouziane
Rachid
R
Milder
Peter
P
Rangaraj
Deepak
D
Cartolano
Anthony
A
Koutsoyannis
Robert
R
Hoe
James C
JC
Püschel
Markus
M
Glick
Madeleine
M
Killey
Robert I
RI
D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008872:Microwaves; D055096:Optical Devices; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*; D013685:Telecommunications / Q000295:instrumentation*