A Demodulation Locking Decision Method Based on Signal-to-Noise Ratio Estimation

Abstract

The invention discloses a demodulation and locking decision method based on signal-to-noise ratio estimation. The digital down-conversion data in the demodulation process of digital signals is used to estimate the signal-to-noise ratio. On this basis, by counting the degree of divergence of the constellation diagram, The corresponding relationship between the signal-to-noise ratio and the signal-to-noise ratio determines whether the current demodulation is locked, and at the same time, determines whether the current lock is normal. Since the present invention has determined the signal-to-noise ratio of the digital down-conversion data, the connection between the signal-to-noise ratio and the divergent state of the constellation diagram is established. If the divergences of the corresponding constellation diagrams are not consistent under a certain signal-to-noise ratio, the traditional method may judge that it has been locked at this time. But using the present invention, the difference between signal-to-noise ratio and divergence can be found. By using the present invention, the parameter adjustment of the demodulation loop can be better guided, thereby being more conducive to the improvement of the demodulation performance.

Description

technical field [0001] The invention relates to the field of signal processing, in particular to a demodulation locking decision method based on signal-to-noise ratio estimation. Background technique [0002] General digital signal demodulation, such as PSK and QAM signals in satellite communications, will use a constellation diagram to show the demodulation effect. If the demodulation result is in a locked state (that is, the clock and the carrier are synchronized), the constellation diagram is relatively convergent. [0003] The judgment of demodulation lock is very important in many occasions. For example, a demodulator with automatic parameter scanning function needs to use the locked judgment result to indicate whether the device performs parameter scanning. [0004] In the carrier locked state, if the carrier loop parameters are not good, the constellation points of the constellation diagram will not be round enough (showing a long strip); in the clock locked state, ...

AI Technical Summary

Problems solved by technology

[0009] Although the above-mentioned traditional locking determination method can determine the basic state of demodulation locking, it cannot determine the locking effect

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