Frequency offset coarse estimation method suitable for low signal-to-noise ratio and high dynamic environment

Abstract

The invention discloses a frequency offset coarse estimation method suitable for a low signal-to-noise ratio and high dynamic environment, and belongs to the technical field of communication. According to the method, the amplitude-frequency characteristic of a forming filter is obtained through a forming factor of the forming filter specified in a communication system in advance, the amplitude-frequency characteristic of the signal received by a receiver is solved, after correlation operation of the amplitude-frequency characteristics is completed, the frequency corresponding to the point withthe maximum correlation is obtained, and the frequency value is the result of frequency offset coarse estimation at the moment. The method is a frequency offset blind estimation method, can be generally used as a first stage of receiver baseband signal processing, can greatly reduce the residual frequency offset of a received signal after frequency offset coarse estimation and compensation, and fully simplifies the subsequent implementation complexity. Compared with the prior art, the frequency offset coarse estimation method disclosed by the invention needs few prerequisites, is low in adaptive signal-to-noise ratio, large in dynamic range and very wide in application scene, and has a very good use value.

Description

technical field [0001] The invention relates to a rough frequency offset estimation method adapted to a low signal-to-noise ratio and high dynamic environment, and belongs to the technical field of communication. Background technique [0002] Satellite mobile communication has the characteristics of high dynamics and low signal-to-noise ratio, which leads to the existence of multi-Puller frequency deviation and high-order frequency change rate in satellite communication signals, which brings difficulties to signal synchronization and demodulation. In satellite mobile communication, due to the fast relative motion between the satellite and the communication terminal, a large Doppler frequency deviation is brought; at the same time, subject to the capabilities of the satellite and the terminal, the symbol rate in mobile satellite communication is often low. The result of the combination of the two leads to the fact that in satellite mobile communication, the Doppler frequency ...

AI Technical Summary

Problems solved by technology

The data-assisted method usually uses pilots (or physical frame headers, unique words, etc.) to estimate the frequency offset. However, in the application background of this scene, the frame structure uses the method of inserting pilots at intervals to deal with the problem of rotor occlusion. As a result, the rate of known data is greatly reduced, combined with its own highly dynamic application environment, it is completely beyond the range of frequency offset estimation by data-assisted methods

For the traditional blind estimation method, the estimation function usually cannot work properly under such a low signal-to-noise ratio

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