Robust DOA Estimation in the Presence of Mutual Coupling effect with Application in Auxiliary Vehicle Positioning

As an important branch of the Internet of Vehicles (IoV), vehicle positioning has drawn extensive attention. Traditional positioning systems based on a global positioning system incur long delays, and may fail due to obstructions. In this article, we propose an auxiliary positioning architecture, whose core is to estimate the direction of arrival (DOA) of signals from landmarks, such as wireless access points, utilizing a sensor array in the vehicle. Due to space limitations, the array may be placed in an arbitrary geometry and may suffer from mutual coupling effects, and it is possible that the effect of mutual coupling between the array elements greatly reduces the independence of the elements of the array, and this effect involves the interaction of each element with its nearby objects. Mutual coupling in antenna arrays can critically degrade the performance of signal processing algorithms. In this paper, a new and accurate form of mutual impedance matrix (MIM) is used to compensate for the effect of mutual coupling in uniform linear arrays (ULA) by a new method based on solving the boundary value problem for all array elements. By using the MIM in the DOA estimation algorithms, these algorithms will be robust to the mutual coupling effect. The simulation results confirm the performance improvement of the proposed DOA estimation algorithm. The proposed architecture can obtain robust self-localization with existing vehicular ad hoc networks, and it can collaborate with other positioning systems to provide a safe driving environment.