The history of orthogonal frequency-division multiplexing [History of Communications]
Orthogonal frequency-division multiplexing (OFDM) is one of those ideas that had been building for a very long time, and became a practical reality when the appearance of mass market applications coincided with the availability of efficient software and electronic technologies. This article describes the background and some of the striking early development of OFDM, with explanation of the motivations for using it. The author presume a broad definition of OFDM as frequency-division multiplexing (FDM) in which subchannels overlap without interfering. It does not not necessarily require the discrete Fourier transform (DFT) or its fast Fourier transform (FFT) computational method.