Self-adaption anti-coherent interference technology based on characteristic component rejection

Abstract

The invention discloses a self-adaption anti-coherent interference technology based on characteristic component rejection. Firstly, characteristic decomposition is carried out on an antenna multichannel receiving data covariance matrix to judge the number of a big characteristic value; then, the characteristic vector corresponding to signals and coherent interference is searched in a characteristic vector group corresponding to the big characteristic value so as to subtract the characteristic vector from the covariance matrix; finally, diagonal loading is carried out on the covariance matrix removing signals and coherent interference components, and the loaded matrix is used for calculating a self-adaption weight, data is weighed, and specific steps are disclosed in the drawing. The method of the invention avoids cancellation of desired signals while inhibiting incoherent interference, does not have array aperture loss and does not need to master the direction priori information of coherent interference. The method only relates to characteristic decomposition and inversion operation but does not relate to high-order cumulant operation, so that the method has simple steps and small calculation amount; the device is simple and has low cost. In addition, the method of the invention receives and utilizes the coherent interference as a wanted signal so as to improve the receiving gain of a target signal, thus owning better receiving performance. The method of the invention can be realized only by downloading a program to a general signal processing board, is easy to popularize and only needs to programme on a programmable signal processing board; thus, the system is convenient to upgrade while the system structure is not changed. The method of the invention can be widely applied to a system with various kinds of receiving channel structures and has popularization and application value.

Description

technical field [0001] The invention relates to an adaptive coherent interference suppression technology in the field of signal processing, which is suitable for signal processing systems with multiple airspace channels, such as phased array radar signal processing systems and communication systems using array antennas, etc., and can be used in non- Target detection in the environment where coherent interference and coherent interference exist simultaneously, to achieve the suppression of non-coherent interference and the utilization of coherent interference. Background technique [0002] In adaptive array signal processing, coherent interference often exists, such as multipath reflection, intelligent interference, etc. At this time, the conventional adaptive beamforming method will cause the desired signal to cancel, resulting in a serious decline in beamforming performance. Therefore, how to effectively suppress coherent interference has always been a difficult point in th...

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Problems solved by technology

However, the former method can only be used in special occasions where the desired signal and coherent interference belong to non-normal distribution while other interference and noise belong to normal distribution, and because this technique needs to perform high-order cumulant estimation, there is still a need Due to the disadvantages of large number of samples and large amount of calculation, there is still a distance between application and engineering practice; the latter method requires prior knowledge of the direction of arrival of the desired signal and coherent interference. In most cases, this prior knowledge is not sufficient. What may be known must be estimated, and direction of arrival estimation for coherent signals is itself a hot and difficult topic, especially in complex environments

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