Reverse burst transmission time estimation method for TDMA (Time Division Multiple Access) communication-in-motion system of low earth orbit satellite

Abstract

The invention discloses a reverse burst sending time estimation method of a transparent forwarding low-orbit satellite TDMA communication-in-motion system. The method comprises the following steps: calculating a function of satellite / master station transmission delay and ephemeris time in advance; according to the expected ephemeris time when the return burst arrives at the target time slot of the master station, estimating the ephemeris time when the return burst arrives at the satellite; estimating a linear approximation function of a function of return uplink transmission delay and ephemeris time in a moving process of the end station within a period of time before the end station reaches the satellite in a return burst; according to the ephemeris time when the return burst arrives at the satellite, estimating the ephemeris time when the return burst is sent; and mapping the ephemeris time for sending the return burst into the local NCR time of the end station according to the mapping relationship between the end station side ephemeris time and the NCR time. According to the method, the sending time of the backward burst can be directly estimated without estimating the transmission delay of the backward link, the accuracy is high, and the calculation is simple and convenient.

Description

technical field [0001] The invention belongs to the technical field of digital communication, and relates to a time synchronization technology of a TDMA satellite communication system, in particular to a method for estimating the return burst sending time of a low-orbit satellite TDMA mobile communication system with transparent forwarding. Background technique [0002] TDMA system is a multi-user communication system based on time division multiple access technology. In the TDMA satellite communication system, the main station plans various time slots of the return link, and allocates dedicated time slots for each end station connected to the network for data transmission. Different end stations share the same physical channel in time division according to time slot planning. Therefore, all end stations need to establish a timing system that is consistent with the master station, so as to accurately identify the time slot and its range planned by the master station, and pr...

AI Technical Summary

Problems solved by technology

Since the terminal station in motion is in motion, at t″ n Previously, it was impossible to know exactly the location of the end station R(t″ n ), and furthermore, it is impossible to accurately estimate the transmission delay τ of the return link RL [n]

Therefore, it is difficult to accurately estimate the sending time of the return burst by using the above method

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