A method and device for identifying aliasing digital signals

Abstract

The embodiment of the invention discloses a method and device for identifying overlapped digital signals. Two-order, four-order and six-order cumulants of standard signals in different modes are calculated in advance; characteristic values of the standard signals in various modes are calculated and stored according to the cumulant result; and the identification process comprises the following steps of calculating a separate matrix by using a natural gradient ICA algorithm according to a received overlapped signal matrix; calculating the overlapped signal matrix by using the separate matrix to obtain a final estimated value matrix of source signals, wherein each component, which is not zero, in the final estimated value matrix of the source signals is a separated source signal; calculating the two-order, four-order and six-order cumulants of each component, which is not zero, and calculating the characteristic value of each component, which is not zero; and determining the modulation manner of each separated source signal according to the characteristic value of each component, which is not zero, and the characteristic values of the standard signals in various modes. By means of the embodiment of the invention, the overlapped signals can be separated; the identification performance of the overlapped signals is improved; and the overlapped signals are demodulated easily.

Description

technical field [0001] The invention relates to the technical field of signal identification in wireless communication, in particular to a method and device for identifying aliased digital signals. Background technique [0002] With the rapid development of wireless communication, the communication system has undergone earth-shaking changes. Accurately identifying the modulation mode of communication signals has gradually become an important research direction for signal analysis and processing. As an intermediate process in the demodulation of unknown signals in communication systems, modulation identification is of great significance to both civilian and military systems. Communication battle. Most of the previous signal modulation identification methods are aimed at a single signal, but with the increasingly complex and diverse communication systems, the modulation identification of aliased digital signals has become an urgent problem to be solved. [0003] There are tw...

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Problems solved by technology

For aliased digital signals, these two identification methods will have a large error and multiple signals are often mistaken for one signal

[0004] That is to say, the existing digital signal identification schemes are mainly aimed at single signals. If they are used to identify aliased digital signals, since the aliased signals cannot be separated, the recognition performance often cannot achieve the desired effect, resulting in failure Identify the modulation of the aliased signal

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