Fig. 1. Schematic diagram of inter-satellite laser interference in the Taiji Program

Fig. 2. Relationship between laser power and modulation depth

Fig. 3. Simulation diagrams of the frequency domain of the beat frequency signal. (a) Sidebands are visible; (b) sidebands are submerged

Fig. 4. Relationships between modulation depth and signal-to-noise ratio of each signal. (a) Relationship between modulation depth and sideband-to-sidelobe signal-to-noise ratio; (b) relationship between modulation depth and main signal-to-sidelobe signal-to-noise ratio; (c) relationship between modulation depth and main signal-to-sideband signal-to-noise ratio

Fig. 5. Structural diagram of communication system parameters

Fig. 6. Schematic diagram of data judgment

Fig. 7. Flow chart of data recovery

Fig. 8. Laser link design (left) and physical diagram of optical path (right)

Fig. 9. Schematic diagram of the signal measured by the phase meter

Fig. 10. Graph of the measurement results of clock noise

Fig. 11. Frequency domain diagram of the beat frequency signal （m_prn=0.2 rad）

Fig. 12. Frequency chart of data acquisition by the phase meter （m_prn=0.2 rad）

Fig. 13. Frequency domain diagram of the beat frequency signal （m_prn=0.1 rad）

Fig. 14. Frequency chart of data acquisition by the phase meter （m_prn=0.1 rad）

Fig. 15. Phase data diagram of the main signal

Fig. 16. Demodulation result of code elements (part one)

Fig. 17. Bit error analysis result (part one)

Fig. 18. Demodulation result of code elements (part two)

Fig. 19. Bit error analysis results (part two)