Determining the optimal geometry of planar antenna arrays for joint estimating the coordinates of two signal sources on azimuth

Abstract

This paper describes a method for reducing errors in estimating the spatial coordinates of radio emission sources. The problem of increasing the accuracy of direction-of-arrival estimation is the most relevant due to the growth in the number of subscribers, as well as the decrease in the frequency resource, while at the same time limiting computing resources. Several approaches to solving this problem are known from the references. However, an approach based on the use of an expression for calculating the Cramer-Rao lower bound is promising. This expression defines the limit of direction-of arrival accuracy, below which no algorithm is able to fall. However, it is possible to lower this limit even lower. In this article, a new expression has been obtained that describes how the location of antenna elements in space affects the magnitude of errors in the direction finding of two signals. It is shown that this dependence is non-linear. Namely, the errors are determined through the difference of cosines from the coordinates of the antennas in the Cartesian system. Thus, antenna arrays have been obtained that can reduce the magnitude of direction-of arrival bearings errors. The paper presents the results of computer simulation to confirm the proposed approach.