MC-DS-CDMA: An Integrated Communication and Navigation Signal for Low Orbit Satellite Constellation

The integration of communication and navigation of LEO satellite constellation is a current research hotspot. The ground 5G positioning signal PRS and positioning system OTDOA cannot be directly used for LEO satellites. This article is based on the design of the 5G CP-OFDM signal system and proposes the MC-DS-CDMA integrated signal system. The navigation, positioning, and timing signals are fused with the communication signals in frequency and common time slots on the waveform. The design parameters and constraints include three dimensions: frequency domain, time domain, and power domain. Finally, after receiving and sampling the MC-DS-CDMA integrated signal, the receiver replicates the navigation positioning signal and correlates it with the received integrated signal. The results show that the communication signal does not affect the correlation function of the navigation and positioning signal. Through correlation peak detection, the pseudo code phase and Doppler measurement of the navigation and positioning signal can be carried out. The pseudo code measurement accuracy is better than 0.12 meter, and the Doppler measurement accuracy is better than 0.5Hz, thus achieving a feasible solution for high-precision navigation and positioning signal fusion generation under the 5G system, providing necessary technical support for the construction of communication and navigation fusion system of low orbit satellite constellation.