Fig. 1. Schematic diagram of MQAM-LFM integrated signal generation principle

Fig. 2. Schematic diagram of integrated system scheme based on light borne terahertz sensing. (a) Spectrum diagram of intermediate frequency SSB integrated signal; (b) spectrum diagram of Mach-Zehnder modulator (MZM) output signal; (c) spectrum diagram of output signal of polarization maintaining coupler; (d) block diagram of offline digital signal processing algorithm at receiving end of communication; (e) block diagram of offline digital signal processing algorithm at radar receiver

Fig. 3. Principle diagram of pulse compression algorithm

Fig. 4. Fuzzy function diagram of LFM/16QAM-LFM signal. (a) Fuzzy function diagram of LFM signal; (b) fuzzy function diagram of 16QAM-LFM signal

Fig. 5. Signal spectrogram. (a) Spectrogram after MZM modulation; (b) spectrogram after coupling output optical signal with another light source

Fig. 6. BER curves of integrated signals and traditional QAM signals with three different modulation formats. (a) BER curve of 16QAM-LFM/16QAM signal: (I) constellation diagram of 16QAM-LFM signal recovery; (Ⅱ) constellation diagram of 16QAM signal recovery; (b) BER curve of 32QAM-LFM/32QAM signal: (I) constellation diagram of 32QAM-LFM signal recovery; (Ⅱ) constellation diagram of 32QAM signal recovery; (c) BER curve of 64QAM-LFM/64QAM signal: (I) constellation diagram of 64QAM-LFM signal recovery; (Ⅱ) constellation diagram of 64QAM signal recovery

Fig. 7. Relationship curve between integrated signal BER and PD input optical power with different modulation formats. (a) BER curves of 16QAM-LFM signal at different baud rates: (I) constellation diagram of 6 GBaud 16QAM-LFM signal recovery; (Ⅱ) constellation diagram of 10 GBaud 16QAM-LFM signal recovery; (b) BER curves of 32QAM-LFM at different baud rates: (I) constellation diagram of 4 GBaud 16QAM-LFM signal recovery; (Ⅱ) constellation diagram of 8 GBaud 16QAM-LFM signal recovery; (c) BER curves of 64QAM-LFM signal at different baud rates: (I) constellation diagram of 2 GBaud 64QAM-LFM signal recovery; (Ⅱ) constellation diagram of 5 GBaud 64QAM-LFM signal recovery

Fig. 8. Relationship curve between output SNR and distance

Fig. 9. Signal spectrum diagram. (a) 32QAM baseband spectrum; (b) 32QAM-LFM signal spectrum; (c) enlarged spectrum of 32QAM-LFM signal at 9-23 GHz

Fig. 10. Perception result graph of LFM/32QAM-LFM signal. (a) Perception result graph of LFM signal; (b) perception result graph of 32QAM-LFM signal

Fig. 11. Perception result graph of LFM/16QAM-LFM signal. (a) Relationship between relative distance and time delay of LFM/16QAM-LFM signal; (b) distance error diagram of LFM/16QAM-LFM signal; (c) pulse compression result of LFM signal at target spacing of 1.4 cm; (d) pulse compression result of 16QAM-LFM signal at target spacing of 1.4 cm

Fig. 12. Communication and perception performances of 32QAM-LFM signal under different roll down factors. (a) Relationship curve between spectral efficiency and distance resolution of 32QAM-LFM signal and roll down factor; (b) constellation diagram of 32QAM-LFM signal recovery when α=0.01; (c) constellation diagram of 32QAM-LFM signal recovery when α=0.1; (d) constellation diagram of 32QAM-LFM signal recovery when α=0.5; (e) constellation diagram of 32QAM-LFM signal recovery when α=1