A high-precision positioning method and device in a distributed mimo radar system

Abstract

The present invention proposes a high-precision positioning method in a distributed MIMO radar system, including: converting the target positioning problem into a maximum likelihood estimation expression; converting the maximum likelihood estimation expression into a convex function form; using semi The estimated value of the target position is obtained by the method of positive definite relaxation; the distance expression from the target to the transmitting antenna and the receiving antenna is expanded by Taylor series by means of Taylor series expansion, and the weighted least square expression is constructed to estimate the target position. Correction. The present invention directly constructs the maximum likelihood expression about the positioning problem to estimate the target position; introduces the method of semi-positive definite programming to realize the accurate estimation of the target position; uses the method of Taylor series expansion to construct the weighted least square estimation of the error term The expression further improves the estimation accuracy of the target position; in summary, the present invention can accurately estimate the position of the target in the case of high noise power.

Description

technical field [0001] The invention belongs to the technical field of wireless mobile communication, in particular to a method for realizing high-precision positioning based on the time difference of arrival of signals in a distributed MIMO radar system. Background technique [0002] The full name of distributed MIMO radar is distributed multiple-input multiple-output radar. The radar system has multiple transmitting units and multiple output units. It uses multiple antennas to transmit waveforms and comprehensively process the received signals of multiple antennas. Compared with the traditional Phased array radar and MIMO radar make more use of the target's spatial angle diversity and other characteristics to improve radar performance. Since the distributed MIMO radar can make full use of the radar cross section of the target and support high-precision target positioning, it has broad application prospects in the fields of target detection, target tracking, and search and ...

AI Technical Summary

Problems solved by technology

Among them, the weighted least squares method and the two-step weighted least squares method are simple to calculate and have closed-form solutions, but the positioning accuracy of the weighted least squares method is low, even in the case of low background noise power, there is still a certain positioning error ; The two-step weighted least squares method corrects the weighted least squares method by constructing the second least squares expression, so that it can obtain good positioning results when the noise power is low, but when the background noise intensity is high, its The positioning accuracy is very unsatisfactory; the restricted least squares method improves the performance of the two-step weighted least squares method under high noise intensity, but this method requires iterative solutions and the convergence cannot be guaranteed. In addition, the algorithm requires a good The initial solution is to ensure the normal operation of the algorithm, so it has higher requirements for the actual positioning system

[0005] In the current research on the positioning problem of the distributed MIMO radar system, the positioning accuracy has very strict requirements on the noise intensity, and the algorithm can only guarantee good positioning accuracy when the noise intensity is low. Once the noise is too high, there will be There is a serious "threshold effect": when the noise intensity reaches a certain level, the positioning error of the algorithm will increase sharply, so the existing positioning algorithms have a very narrow application range in actual work

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