Receiving Technology of Multi-target TTC Signals Using the Unique PRN Code

Low earth orbit (LEO) satellites have broad application prospects in the 5G / 6G communication era due to their high coverage. From the simulation of a constellation of 2000 LEO satellites, the minimum mean value of passing through the same antenna in one minute is more than 60, which far exceeds the monitoring capabilities of telemetry, track and command (TTC) stations. Code Division Multiple Access (CDMA) technology wastes a lot of hardware resources, and Frequency Division Multiple Access (FDMA) technology needs frequency band resources, which are not applicable to this scenario. In this paper, we analyze the theoretical equal E_b/N₀ of multiple access interference. According to the frequency information of the orbit of LEO satellite, and the characteristics of burst mode and large time slot interval of TTC signals, we design a scheme of parallel access of multiple signals by using the unique pseudorandom (PRN) code. Under the existing conditions, this solution greatly improves the monitoring capability of the ground station and reduces the hardware resource consumption of the ground station. We analyze access capabilities based on actual application scenarios. Simulation results show that the scheme can save 80% of hardware resources under the same monitoring capability.