A near-far field unified positioning method based on angle of arrival

Abstract

The invention discloses a unified positioning method for near and far fields based on the angle of arrival, which re-expresses the position of the target source by establishing a modified polar coordinate system, and establishes a unified positioning model for the near and far fields; The field nonlinear positioning 3D model is transformed into a linear model, and the hybrid semi-positive definite / second-order cone programming problem is established by using convex relaxation technology, and the coordinate position estimation of the target source in the near field and the azimuth angle estimation and pitch angle of the target source in the far field are obtained by solving the problem Estimation; by obtaining the theoretical value of the deviation mean value of the near-field nonlinear positioning 3D model based on the angle of arrival, an approximate unbiased estimate of the coordinate position of the target source in the near-field is obtained; the advantage is that it is not necessary to know whether the target source is in the near-field or The prior knowledge of the far field can obtain an approximate unbiased estimate of the target source position with a small amount of calculation.

Description

technical field [0001] The invention relates to a near and far field unified positioning method, in particular to a near and far field unified positioning method based on an angle of arrival (Angle-of-Arrive, AOA) in a wireless sensor network. Background technique [0002] Target localization is a very important technology in wireless sensor networks. The target to be located is called the source. In traditional object localization, near-field localization and far-field localization are regarded as two different localization scenarios. In near-field localization, the target source is relatively close to the sensor array, and the signal propagation paths from the sensor to the target source intersect to obtain the target source position, so near-field localization is usually regarded as point localization. In far-field positioning, the target source is far away from the sensor array, and the signal propagation path from the sensor to the target source is approximately paral...

AI Technical Summary

Problems solved by technology

However, the measurement model for angle-of-arrival-based positioning is highly nonlinear

To solve nonlinear problems, a direct grid search method can be used to try all possible target source positions to achieve the optimal estimate. However, although the optimal value can be obtained in this way, the calculation is huge

Another solution to nonlinear problems is through an iterative algorithm. The iterative algorithm requires a reliable initial value to start the iteration. The selection of the initial value determines the performance of the entire iterative algorithm, and the selection of a suitable initial value is relatively difficult.

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