Implementation of an IFFT for an Optical OFDM Transmitter with 12.1 Gbit/s

This paper describes the design of an inverse discrete Fourier transform (IDFT) for an optical orthogonal frequency division multiplexing (O-OFDM) transmitter for a bitrate of 12.1Gbit/s. The complete transmitter was implemented on a Virtex 5 FX200T field programmable gate array (FPGA) from Xilinx. The main part of the transmitter, which needs the most signal processing hardware resources, is the IDFT. A 256-point radix-2 inverse fast Fourier transform (IFFT) was implemented.