Spectrally Efficient Multiplexing - OFDM

Abstract

This chapter provides an introduction to the fundamentals of orthogonal frequency-division multiplexing (OFDM) in optical communication, including its basic mathematical formulation, discrete Fourier transform (DFT) implementation, cyclic prefix (CP), spectral efficiency (SE), and peak-to-average power ratio (PAPR) characteristics. It reviews two major schemes of OFDM: coherent optical OFDM (CO-OFDM) and direct-detection optical OFDM (DDO-OFDM) that are popular and have been widely adopted by the optical communications. By utilizing the multiple-input-multiple-output (MIMO) algorithm in digital signal processing (DSP), the capacity of CO-OFDM system can be doubled by using polarization-divis..