Timing synchronization method for feed link of low-earth-orbit satellite

Abstract

The invention relates to the technical field of timing synchronization, in particular to a timing synchronization method for a feed link of a low-earth-orbit satellite, and aims at overcoming timing deviation of a spread spectrum signal of a low-orbit satellite feed link by providing a low-orbit satellite feed link spread spectrum signal timing synchronization technology, and carrying out timing synchronization on an input spread spectrum signal by using a method of combining Gardner timing synchronization and de-spreading. Firstly, signals pass through a Farrow filter, and decimal interval interpolation is output according to an NCO numerical control oscillator; and the output interpolation is de-spread, errors are extracted by using a square timing error estimation algorithm, high-frequency components in a sampling clock frequency offset estimation value are filtered through a loop filter, a CO register is updated according to the timing errors to provide required decimal intervals and interpolation base points for an interpolator, signals are ensured to keep timing synchronization, and the effectiveness of signal transmission is improved.

Description

technical field [0001] The invention relates to the technical field of timing synchronization, in particular to a method for timing synchronization of low-orbit satellite feeder links. Background technique [0002] With the ever-increasing demand for mobile communication, satellite communication and burst communication services in the communication industry, the research on bit synchronization technology is becoming more and more important. In recent decades, the research work on this technology has attracted the attention of experts and scholars from all over the world. [0003] The bit synchronization method used in the early days is to insert a pilot at the position where the spectrum of each symbol at the sending end is zero, and then use a narrowband filter to extract the frequency component at the receiving end to perform symbol synchronization. This is the so-called insertion type. Synchronous method, which is a data-assisted algorithm. The advantage of this algorith...

AI Technical Summary

Problems solved by technology

The Gardner bit synchronization algorithm was originally proposed for binary and quaternary digital phase modulation signals; but at present, the signal transmission performance is not high, and the signal at the best sampling position cannot be accurately extracted, the signal is easily interfered, and the complexity is high. The calculation accuracy is low, the phase error correction accuracy is not high, etc.

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