Digital modulation signal differential constellation diagram information extraction and modulation identification method

Abstract

The digital modulation signal differential constellation information extraction and modulation identification method disclosed by the invention has strong anti-noise energy and is not influenced by carrier frequency estimation deviation. According to the technical scheme, the method comprises the following steps: firstly, converting an intercepted signal into a complex form, constructing a code element truncated data matrix A, performing singular value decomposition on the A, and counting the number of larger singular values; secondly, grouping the elements in the first left singular vector according to module values; then, extracting differential constellation information corresponding to each group of module value elements; and finally, according to the number of larger singular values, the number of module value groups of the first left singular vector elements, and the number of differential phase peak values and phase values of each group of elements, completing extraction of modulation information such as amplitude and phase contained in the intercepted data, and realizing identification of a signal modulation mode. According to the invention, the defects of limited identification types and inconvenient expansion are avoided. Besides, automation degree of the receiver can be improved, and the real-time interception capability is enhanced.

Description

technical field [0001] The present invention is mainly aimed at the identification of digital modulation signals in complex electromagnetic environments, and mainly relates to a method for extracting differential constellation information and modulation identification of digital modulation signals based on Singular Value Decomposition (SVD) under the condition of low signal-to-noise ratio. Background technique [0002] With the advancement of radio communication technology and the development of various modulation methods, as well as the increase in the demand for informatization in various fields, unknown signals of different frequency bands and patterns and various noises are intertwined, making the electromagnetic environment complex and dense. The signal modulation constellation diagram contains the amplitude and phase information of the modulated signal, as well as the filter response, the nonlinear effect of the power amplifier and other linear and nonlinear coherent fa...

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Problems solved by technology

There are three deficiencies in the above-mentioned prior art: First, the applicability is insufficient. The existing signal identification method based on a constellation diagram is only effective for a small number of modulation types, and the types of identification are limited. There is a carrier offset when extracting the constellation diagram. , the impact of noise; second, the computational complexity is high, signal synchronization is required, and frequency offset correction, clustering methods, etc. The constellation diagram information acquisition technology at the best sampling time cannot complete the energy accumulation of multiple sampling points, and the anti-noise ability is not good

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