Feedback Circuit Regulation Inspired Loop Filter Coefficient Regulation Algorithm in Satellite Internet of Things

Paired carrier multiple access technology (PCMA) is a frequency multiplexing technology used in satellite communication, which can provide double communication capacity without changing the original multiple access mode and modulation code of the communication system, and hardly affect the system performance. The key technology of PCMA is parameter estimation of self-interfering signal. This paper studies the influence of timing synchronization on system performance and the measurement of performance index in PCMA system, and presents a timing synchronization tracking algorithm using feedback circuit to adjust loop filter coefficients. Verified by the simulation results, the method of guiding loop convergence can solve the contradiction between loop convergence time and convergence oscillation amplitude to some extent, and the multilevel variable length correlator is used instead of the long correlator to reduce the resource consumption.