Recognition method of M-ary orthogonal amplitude modulation

Abstract

The invention discloses a recognition method of M-ary orthogonal amplitude modulation, which is mainly used for solving the problems of complicated computational complexity and low recognition rate of the existing recognition way of MQAM within-class signal modulation. The implementation process is as follows: firstly carrying out over-sampling on received signals y(t) for obtaining a sampling sequence y(n), thereby changing continuous signals to discrete signals; calculating values of two-order moment, four-order moment and six-order moment of a received sampling signal y(n); utilizing the values of the two-order moment, the four-order moment and the six-order moment for calculating the combined moment m23; taking a solid part of the combined moment m23 as a feature vector m23 of the received sampled signal; calculating theoretical values m' of the QAM feature vectors of all the orders; calculating the decision threshold of the modulation way through the theoretical values m' of the QAM feature vectors of all the orders; and determining the modulation way of the received signals according to the feature vector m23 of the received sampling signal and the decision threshold of the modulation way. The recognition rate of the method for recognizing the MQAM within-class signals under the environment of a Rayleigh fading channel and low signal to noise ratio can achieve 100% above 5dB, thereby being higher than the existing other methods.

Description

technical field [0001] The invention belongs to the technical field of communication, and relates to a recognition method for multi-ary quadrature amplitude modulation MQAM signals under the conditions of Rayleigh fading channel and low signal-to-noise ratio, which should be used in automatic pattern recognition AMC. Background technique [0002] Automatic mode recognition refers to a technology that automatically identifies the modulation type of the signal by observing and analyzing the sampled data of the received signal in a fading channel. AMC is becoming more and more important in both military and civilian applications. For example, in electronic information warfare, signal spectrum monitoring management and software radio, it is necessary to judge the modulation mode of communication signals and estimate the corresponding modulation under the premise of unknown modulation information. parameters to be demodulated. At present, there are few researches on intra-class ...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to overcome the low signal-to-noise ratio and Rayleigh channel in the existing MQAM class intra-signal identification field, the identification rate is low, and the calculation is complicated, and a multi-ary quadrature amplitude modulation identification method is proposed. The first-order moment, the fourth-order moment, and the sixth-order moment are combined into a new eigenvector to distinguish the method of the MQAM class signal, so as to realize the identification of the MQAM class signal under the condition of Rayleigh channel and low signal-to-noise ratio, and improve wireless communication. Accuracy and Validity of Transmissions

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