High-precision positioning method and device in distributed MIMO radar systems

Abstract

The invention provides a high-precision positioning method in distributed MIMO radar systems. The high-precision positioning method comprises the steps: a target positioning problem is converted intoa maximum likelihood estimation expression; the maximum likelihood estimation expression is converted into a convex function mode; an estimated value of a target position is obtained through a semi-definite relaxation method; and Taylor series expansion is conducted on a distance expression from a target to a transmitting antenna and a receiving antenna in a Taylor series expansion mode, and a weighted least square expression is constructed to correct the estimated value of the target position. The maximum likelihood expression related to the positioning problem is directly constructed to estimate the target position; a semi-definite programming method is introduced to accurately estimate the target position; the weighted least square estimation expression related to an error term is constructed through a Taylor series expansion method, and the estimation precision of the target position is further improved; and to sum up, the position of the target can be accurately estimated 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

Images