Signal power estimation method based on oblique projection operator

Abstract

The invention belongs to the technical field of signal processing and relates to a signal power estimation method based on an oblique projection operator. The signal power estimation method comprisesfirstly obtaining signal and interference azimuths and the spatial noise power estimation according to a spatial spectrum direction finding result; then subtracting a noise component in a data autocorrelation matrix according to the spatial spectrum estimation result, and constructing an oblique projection operator with the azimuth steering vector of a target signal as a value domain and the azimuth steering vector of an interference signal a as a zero space; and finally reconstructing the signal power estimator according to the oblique projection operator. Compared with a signal area integration method, an alternate projection method and a steering vector orthogonal approximation method, the method of the invention can effectively remove the residual power of a spatial interference signaland achieve accurate signal power estimation. Since eigen decomposition is not required, the amount of calculation can be greatly reduced, and the power estimation performance is still good in the case where the incoming wave direction of the interference signal is uncertain.

Description

technical field [0001] The invention belongs to the technical field of signal processing, and relates to a signal power estimation method based on an oblique projection operator. Background technique [0002] With the development of radio technology, applications such as mobile communication, broadcasting, television, navigation, remote control telemetry, and radar have gradually covered all aspects of national defense and people's daily life. Researchers use antenna arrays to convert time-domain sampling into space-time sampling. Extend many theoretical results of signal processing in the time domain to the air domain. An important scenario in array signal processing is to accurately estimate the target signal power to reconstruct the interference-plus-noise covariance matrix and design robust adaptive beamforming weights. In space signal power estimation, there are three commonly used methods: signal area integral method, alternate projection method and steering vector or...

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Problems solved by technology

However, this assumption does not hold in practice, and the asymptotic orthogonality between steering vectors will produce power residues, which will affect the final estimation results

[0006] Although the above space signal power estimation methods can estimate the signal power more accurately to a certain extent, they are inevitably affected by the residual power of other interfering signals in the space, making the estimated signal power inaccurate

However, this inaccuracy will have a great impact on the array signal processing effect. In the beamforming process, there will be a large deviation between the weight design of the final adaptive beamforming and the ideal weight value, resulting in a relatively large signal-to-noise ratio at the receiving end. The theoretical value is greatly reduced, seriously affecting the overall performance of the system

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