page13
"A"
DFT
DFT-1
~1950 analog multitone modem for ionospheric links
~1990 wavelength-division multiplex (WDM) in optical fibers
~2000 numerical DFT → OFDM WLAN (WiFi) 802.11a (FFT)
Wideband
signal
Wideband
signal
N narrowband
signals
LNA