A carrier frequency synchronization method suitable for millimeter wave inter-satellite link

Abstract

The invention discloses a carrier frequency synchronization method suitable for a millimeter wave inter-satellite link, and belongs to the field of inter-satellite communication systems. The method includes firstly, constructing a millimeter wave inter-satellite link communication scene, and any two satellites transmitting information through an inter-satellite link; next, launching the satellitefor the current time, the high-frequency wireless frame reaching a receiving end of another satellite through a millimeter wave inter-satellite link, obtaining a digital signal with carrier frequencyoffset after sampling, extracting an STF sequence rstf [n] of the current wireless frame, demodulating the sequence rstf [n] , extracting a phase difference, and obtaining a coarse frequency offset estimated value of the current wireless frame; and finally, carrying out fine estimation on the frequency offset estimation value again and compensating to the current wireless frame to realize carrierfrequency synchronization of the current frame; and sequentially selecting a next wireless frame, repeatedly extracting the STF sequence rstf [n], carrying out coarse estimation and fine estimation offrequency offset, and compensating a final estimation value to each frame, thereby realizing carrier frequency synchronization of each frame. According to the method, a more stable and accurate frequency offset estimation value can be obtained, so that the system performance is effectively improved.

Description

technical field [0001] The invention belongs to the field of inter-satellite communication systems, and relates to the problem of carrier frequency synchronization at a receiving end, in particular to a carrier frequency synchronization method suitable for millimeter-wave inter-satellite links. Background technique [0002] The available bandwidth of the mmWave communication system is large, so it can support high-speed data rate transmission. However, long-distance and high-capacity mmWave communication needs to ensure accurate signal capture and demodulation. Carrier synchronization is one of the key technologies in receiver digital communication modems. [0003] In the inter-satellite communication network, the inter-satellite link is an important channel for information transmission. However, due to the high-speed relative motion between the satellites, the high-speed relative motion of the satellites produces a serious Doppler frequency shift, so that there is a carri...

AI Technical Summary

Problems solved by technology

However, due to the high-speed relative motion between the satellites, the high-speed relative motion of the satellites produces a serious Doppler frequency shift, so that there is a carrier frequency deviation with a high dynamic range in the receiver signal. This deviation is relative to the carrier deviation of the ground communication system. Very large, it has a great impact on data reception, demodulation, and judgment. If this deviation cannot be offset, it will have a great impact on communication

In addition, due to the limited transmission power of the satellite, the signal-to-noise ratio of the inter-satellite link is low

[0004] The carrier synchronization technology currently applied to the ground communication system and the satellite-ground communication system mainly uses the known sequence of the wireless frame to extract the phase difference for frequency offset estimation, and the estimation range and estimation accuracy of the frequency offset cannot be guaranteed at the same time.

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