A Time-Frequency Cooperative Filtering Method and System Applied to Identification of Communication Modulation Mode

Abstract

The invention relates to a time-frequency collaborative filtering method and system applied to identification of communication modulation modes. The filtering method includes: determining an analytical signal; estimating the instantaneous frequency of the analytical signal to obtain the instantaneous frequency of the analytical signal; The analytical signal is input to the down-conversion mixer, and the frequency of the mixer adopts the instantaneous frequency of the signal to obtain the output data sequence of the down-conversion mixer; the converted down-conversion mixer output data sequence is input to the low-pass frequency filter to obtain the filtered data sequence; input the filtered data sequence to the up-conversion mixer to obtain a high signal-to-noise ratio analytical signal after collaborative filtering. The above method in the present invention can effectively filter out interference noise and improve the signal-to-noise ratio.

Description

technical field [0001] The invention relates to the field of communication modulation, in particular to a time-frequency collaborative filtering method and system applied to identification of communication modulation modes. Background technique [0002] The identification of communication modulation mode is to judge the modulation mode of communication signal and estimate the corresponding modulation parameters under the premise of unknown modulation information content. In terms of civilian use, relevant functional departments can identify unregistered transmitters by analyzing received radio signals; Interception of enemy communications, or deceptive jamming of enemy communications. [0003] The composition of the communication modulation identification system mainly includes signal receiver, data preprocessing, feature extraction, classification identification and display. The purpose of preprocessing is to weaken the influence of noise and enhance useful information fe...

AI Technical Summary

Problems solved by technology

Since the frequency of the frequency modulation signal changes, if the passband bandwidth of the bandpass filter is set too small, although the influence of white noise can be greatly reduced, useful signals may be filtered out; if the passbandbandwidth of the bandpass filter is too large, It will make more noise pass through the filter, which is not conducive to the improvement of signal-to-noise ratio

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