Fig. 1. Structure of the 1-bit second-order delta-sigma modulator with a CRFB configuration.

Fig. 2. (a) STF, NTF and (b) the pole-zero pattern of the delta-sigma modulator.

Fig. 3. Experimental setup and DSP block diagram of the proposed IM/DD MMW-RoF system with DSM.

Fig. 4. Power spectral density of the signal (a) after DSM and (b) captured by the OSC.

Fig. 5. (a) BER versus baud rate when the input optical power into the MZM is 7 dBm; (b) BER versus input optical power into the MZM when the baud rate is 10 Gbaud; (c) recovered constellation diagrams for different QAM orders.