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).
Subject(s)
Optical Devices , Signal Processing, Computer-Assisted/instrumentation , Telecommunications/instrumentation , Computer-Aided Design , Equipment Design , Equipment Failure Analysis , Microwaves , Reproducibility of Results , Sensitivity and SpecificityABSTRACT
A 10.7 Gb/s electronic predistortion transmitter using FPGA-based real time 2 Samples/bit digital signal processing based on 55-tap finite impulse response filters is described. Transmission over 1200 km of standard single-mode fiber without optical dispersion compensation is demonstrated with an OSNR penalty of only 2.5 dB, compared with back-to- back operation.
