A method for identifying the modulation mode of satellite communication signals

Abstract

The invention discloses a method for recognizing a satellite communication signal modulation way. According to the scheme, the method comprises the following steps: 1, filtering a received signal to obtain a signal to be recognized; performing power spectrum smoothening, carrier frequency estimation and coherent demodulation on the signal to be recognized to obtain a demodulated signal; 3, estimating the code element rate of the demodulated signal; 4, determining whether the received signal is a binary phase shift keying signal or not by using a square spectrum; 5, determining whether the received signal is a quaternary phase shift keying signal or a hexadecimal quadrature amplitude modulation signal by using a signal quartic spectrum, carrier frequency and the code element rate; 6, determining whether the received signal is an octonary phase shift keying signal or not by using a signal eightfold spectrum; and 7, determining whether the received signal is a hexadecimal amplitude phase shift keying signal or not by using a signal duodenary spectrum, the carrier frequency and the code element rate. The method has high recognition accuracy, and can be applied to real-time monitoring of satellite communication signals. Through adoption of the method, totally-blind real-time recognition of the satellite communication signal modulation way can be realized.

Description

technical field [0001] The invention belongs to the technical field of satellite communication, in particular to a method for identifying modulation modes of satellite communication signals, which can be used for real-time monitoring of satellite communication signals. Background technique [0002] In the field of satellite signal communication and telemetry, the identification of modulation mode is of great significance. It is a necessary prerequisite for the demodulator to correctly demodulate the signal and obtain the information of the satellite communication link. Commonly used satellite communication signals include binary phase shift keying BPSK signal, quaternary phase shift keying QPSK signal, octal phase shift keying 8PSK signal and sixteen quadrature amplitude modulation 16QAM signal. The development of transponder and antenna technology has made the application of high-order modulation more and more extensive. For example, the new generation of digital satellite ...

AI Technical Summary

Problems solved by technology

[0006] 1. The extraction of the feature parameters used often requires more prior knowledge, and blind recognition cannot be performed;

[0007] 2. The influence of raised cosine shaping on signal classification characteristics is not considered, which makes the correct recognition rate of the algorithm decrease or even fail;

[0008] 3. The algorithm is complicated, and it is difficult to recognize the modulation mode in real time;

[0009] 4. The high-order cumulant is greatly affected by the frequency offset, which makes the correct recognition rate of the algorithm low in the presence of frequency offset

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