| abstract |
A method for determining a time-frequency correction period of an uplink signal of a low-orbit constellation, comprising the steps of: 1) determining the dwell time of a ground terminal in each beam; 2) an uplink signal sent by the ground terminal to a satellite, The Doppler frequency offset of the signal in the direction of signal propagation, to determine the maximum Doppler rate of change; 3) According to the dwell time, determine the time correction period; 4) According to the maximum Doppler rate of change, determine the frequency correction 5) Determine the time-frequency correction period according to the time-frequency correction period and the frequency-correction period. According to the time-frequency correction period, the uplink signal is simultaneously subjected to frequency correction processing and time correction processing once in each period. The invention analyzes the dwell time, Doppler frequency offset and Doppler change rate of the terminal ground terminal in the beam, ensures that the starting point of the ground uplink service burst signal received by the satellite falls within the time slot protection, and ensures that the uplink frequency offset It can meet the accuracy requirements after using unique word correction. |