Fig. 1From: Research on optical 32QAM-OFDM-PON access scheme with different numbers of sub-carriers using DMT modulationBlock diagrams of the DMT modulation (a) and demodulation (b) of 32QAM-OFDM signals. DMT: discrete multitone; IFFT: inverse fast fourier transform; FFT: fast fourier transform; DAC: Digital to analog converter; ADC: Analog to digital converterBack to article page